Insulating element and method and plant for producing and packaging

ABSTRACT

A mineral fiber plate product is produced by producing a first non-woven mineral fiber web containing mineral fibers predominantly arranged in a first longitudinal direction and segments of the first mineral fiber web are arranged in a partly mutually overlapping relationship for producing a second non-woven mineral fiber web, which contains mineral fibers generally transversally relative to one another. The second mineral fiber web is folded transversely for producing a third non-woven mineral fiber web. The third non-woven mineral fiber web is cured for producing a cured non-woven mineral fiber web from which a mineral fiber plate, or alternatively, a tubular insulating element is cut. In packaging, the volume of the mineral fiber plate may be reduced to 40%-60%.

The present invention generally relates to the technical field ofproducing mineral fiber plates. Mineral fibers generally comprise fiberssuch as rockwool fibers, glass fibers, etc. More precisely, the presentinvention relates to a novel technique of producing a mineralfiber-insulating web from which e.g. mineral fiber-insulating plates orproducts are cut. The mineral fiber plates or products produced from thenon-woven mineral fiber web produced in accordance with the presentinvention exhibit advantageous characteristics as to mechanicalperformance, such as modulus of elasticity and strength, low weight,reduced content of bonding agents, and good thermal-insulating property.

Non-woven mineral fiber webs are normally hitherto produced ashomogeneous webs, i.e. webs in which the mineral fibers of which themineral fiber web is composed, are generally orientated in a singlepredominant orientation which is determined by the orientation of theproduction line on which the mineral fiber web is produced andtransmitted during the process of producing the mineral fiber web. Theproduct made from a homogeneous mineral fiber web exhibitscharacteristics which are determined by the integrity of the mineralfiber web and which are to a high degree determined by the binding ofthe mineral fibers within the mineral fiber plate produced from themineral fiber web, and further to a high degree determined by thedensity of the mineral fibers of the mineral fiber plate.

The advantageous characteristics of mineral fiber plates of a differentstructure has to some extent already been realized as techniques for theproduction of mineral fiber plates in which the mineral fibers areorientated in an overall orientation different from the orientationdetermined by the production line, has been devised, vide PublishedInternational Patent Application, International Application No.PCT/DK91/00383, International Publication No. WO 92/10602 and U.S. Pat.No. 4,950,355. Reference is made to the above patent application andpatent, and the above U.S. patent is hereby incorporated in the presentspecification by reference.

An object of the present invention is to provide a novel method ofproducing a mineral fiber web from which mineral fiber plates may be cutwhich method renders it possible in an online production plant toproduce mineral fiber plates which are of a composite structureproviding distinct advantages as compared to the prior art mineralfiber-containing plates.

A further object of the present invention is to provide a novel methodof producing a tubular insulating element which method renders itpossible to produce tubular insulating elements exhibiting specificcharacteristics in terms of mechanical characteristics, includingflexibility and mechanical strength, and thermal insulating properties.

A particular advantage of the present invention relates to the novelmineral fiber plate according to the present invention and produced inaccordance with the method according to the present invention which ascompared to prior art mineral fiber plates contains less mineral fibersand is consequently less costly than the prior art mineral fiber plates,still exhibiting advantages as compared to the prior art mineral fiberplates relating to mechanical strength and thermal-insulatingproperties.

A particular feature of the present invention relates to the fact thatthe novel mineral fiber plate according to the present invention andproduced in accordance with the method according to the presentinvention is produceable from less mineral fibers or less material ascompared to the prior art mineral fiber plate still providing the sameproperties as the prior art mineral fiber plate regarding mechanicalstrength and thermal-insulating properties, thus, providing a morelightweight and less voluminous mineral fiber plate product as comparedto the prior art mineral fiber plate product reducing transport, storageand handling costs.

A further advantage of the present invention relates to the fact thatthe novel mineral fiber plate according to the present invention andproduced in accordance with the method according to the presentinvention is a mineral fiber plate product exhibiting on the one handcharacteristics as to mechanical strength substantially equal to thebest prior art high strength non-woven mineral fiber plate products ofthe same or substantially the same overall dimensions and on the otherhand characteristics as to thermal insulating properties equal to thebest prior art high-insulating mineral fiber plate products of the sameor substantially the same overall dimensions.

A further advantage of the present invention relates to the fact thatthe novel tubular insulating element according to the present inventionand produced in accordance with the method according to the presentinvention may constitute a tubular insulating element which is easilyadapted to specific geometric application requirements as the tubularinsulating element is easily compressable and deformable due to a highflexibility of the tubular insulating element along the longitudinaldirection thereof or any arbitrary direction relative to thelongitudinal direction of the tubular insulating element, however, stillexhibiting excellent characteristics as to mechanical strength andinsulating properties.

A further feature of the present invention relates to the fact that thenovel mineral fiber plate according to the present invention andproduced in accordance with the method according to the presentinvention may constitute an insulating plate which is easily adapted tospecific geometric application requirements as the insulating plate iseasily compressible and deformable, however, still exhibiting excellentcharacteristics as to mechanical strength and insulating properties.

A further feature of the present invention relates to the novel mineralfiber plate according to the present invention which exhibits highcompressibility and high compactability and further exhibits thecapability of substantially recovering perfectly after the mineral fiberplate has been compacted for an elongated period of time.

A further feature of the present invention relates to the novel mineralfiber plate according to the present invention which exhibits excellentcharacteristics as to mechanical strength, allowing the mineral fiberplate to be confined within a packaging foil without causing any part ofthe mineral fiber plate, such as the outer edges or corners of themineral fiber plate, to be permanently deformed or damaged through themechanical impact produced by the packaging foil.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features which will beevident from the below detailed description of present preferredembodiments of the invention are obtained by a method according to thepresent invention comprising the following steps:

a) producing a first non-woven mineral fiber web defining a firstlongitudinal direction parallel with the first mineral fiber web and afirst transversal direction parallel with the first mineral fiber web,the first mineral fiber web containing mineral fibers predominantlyarranged generally in the first longitudinal direction thereof andincluding a first curable bonding agent,

b) moving the first mineral fiber web in the first longitudinaldirection,

c) arranging segments of the first mineral fiber web in partly mutuallyoverlapping relationship and transversely relative to the firstlongitudinal direction and the first transversal direction so as toproduce a second non-woven mineral fiber web, the second mineral fiberweb defining a second longitudinal direction and a second transversaldirection and containing mineral fibers predominantly arranged generallytransversely relative to the second longitudinal direction and thesecond transversal direction and generally transversely relative to oneanother,

d) moving the second mineral fiber web in the second longitudinaldirection,

e) folding the second mineral fiber web transversely relative to thesecond longitudinal direction and parallel with the second transversaldirection so as to produce a third non-woven mineral fiber web, thethird mineral fiber web containing mineral fibers predominantly arrangedgenerally transversely relative to one another and generallytransversely relative to the second longitudinal direction and thesecond transversal direction,

f) moving the third non-woven mineral fiber web in the secondlongitudinal direction, and

g) curing the first curable bonding agent so as to cause the mineralfibers of the third mineral fiber web to bond to one another, therebyforming the cured non-woven mineral fiber web.

In the present context, a direction defined as a direction beingtransversely relative to a specific reference direction defines anangular relationship between the direction in question and the referencedirection. More specifically, in the present context, a transverserelationship between any two directions means that an angle is definedbetween the directions in question, the angle being larger than 0° andsmaller than 90°. Thus, in the present context, a transverse directionmeans a direction different from a longitudinal or transversaldirection, i.e. an intermediate direction relative to the longitudinalor transversal direction constituting the reference direction inquestion.

In accordance with the method according to the present invention, themineral fibers of the third mineral fiber web which is cured for theformation of the cured non-woven mineral fiber web are arranged orpositioned predominantly providing internal crossings of mineral fiberswithin the third mineral fiber web which crossings on the one handprovide final mineral fiber products exhibiting mechanicalcharacteristics in terms of modulus of elasticity and strength equal tothe mechanical characteristics of conventional high strength mineralfiber products such as the products known from the above-mentionedpublished international patent application and which crossings on theother hand provide final mineral fiber products exhibitingcharacteristics in terms of insulating properties equal to theinsulating properties of conventional high insulating mineral fiberproducts.

The step of producing the second non-woven mineral fiber web from thefirst non-woven mineral fiber web, i.e. the above-described step c) maybe carried out in any appropriate way fulfilling the intentional purposeof transforming the first mineral fiber web containing mineral fiberspredominantly arranged or orientated along the first longitudinaldirection defined by the first mineral fiber web and constituting theoverall direction of transportation or motion of the first mineral fiberweb into the second mineral finer web containing mineral fiberspredominantly arranged or orientated transversely relative to oneanother and transversely relative to the second longitudinal directiondefined by the second mineral fiber web and constituting the overalldirection of transportation or motion of the second mineral fiber web.

According to a first embodiment of the method according to the presentinvention, the arranging of the segments of the first mineral fiber webin partly mutually overlapping relationship of step c) comprises theinitial step of cutting the first mineral fiber web into the segments.

According to a second and presently preferred embodiment of the methodaccording to the present invention, the arranging of the segments of thefirst mineral fiber web in partly mutually overlapping relationship ofstep c) comprises folding the segments of the first mineral fiber webtransversely relative to the first longitudinal direction and the firsttransversal direction.

The angular position of the segments relative to the second longitudinaldirection and relative to the speed of transportation or motion of thesecond mineral fiber web determines the arranging of the segments of thefirst mineral fiber web in partly mutually overlapping relationship inthe step of producing the second mineral fiber web. For providing asecond mineral fiber web containing mineral fibers producing an adequateinternal crossing of the mineral fibers of the second mineral fiber web,the arranging of the segments of the first mineral fiber web in partlymutually overlapping relationship of step c) being performed so as toposition the segments of the first mineral fiber web along a directiondefining an angle larger than 0° and smaller than 90° relative to thesecond transversal direction, such as an angle of the order of 10-60°,preferably of the order of 20-50°.

The second mineral fiber web may be folded in any appropriate anglerelative to the second longitudinal direction for providing a specificangular relation between the segments of the second mineral fiber weband the second longitudinal direction and consequently between themineral fibers of the third mineral fiber web and the longitudinaldirection thereof. However, the folding of the second mineral fiber webof step e) is performed preferably as a transverse folding relative tothe second longitudinal direction so as to produce the third mineralfiber web including the segments originating from the first mineralfiber web arranged or positioned substantially perpendicular relative tothe longitudinal direction of the third mineral fiber web, i.e. thesecond longitudinal direction.

The product or products produced in accordance with the method accordingto the present invention are preferably products including a fairlysmall amount of mineral fibers as compared to conventional productsexhibiting similar characteristics as the product according to thepresent invention in terms of mechanical strength and insulatingproperties. Thus, the first mineral fiber web is preferably a mineralfiber web of a low area weight, such as an area weight of 0.1-1.0 kg/m²,preferably 0.2-0.6 kg/m². Similarly, the second mineral fiber web ispreferably a mineral fiber web of an area weight of the order of 0.3-3.0kg/m², preferably 0.5-2.0 kg/m².

In accordance with the technique described in the above-mentionedpublished international patent application, application No.PCT/DK91/00383, publication No. WO 92/10602, the second and thirdmineral fiber webs are preferably exposed to compacting and compressionin order to provide more compact and more homogeneous mineral fiberwebs. The compacting and compression may include height compression,longitudinal compression, transversal compression and combinationsthereof. Thus, the method according to the present invention preferablyfurther comprises the additional step of height compressing the secondmineral fiber web produced in step c) by arranging the segments of thefirst mineral fiber web in partly mutually overlapping relationship andtransversely relative to the first longitudinal direction of the firstmineral fiber web.

Further preferably, the method according to the present inventioncomprises the additional step of longitudinally compressing the secondmineral fiber web produced in step c) and additionally or alternativelythe additional step of transversally compressing the second mineralfiber web produced in step c).

The compacting and compression may further or alternatively comprise theadditional step of height compressing the third mineral fiber webproduced in step e).

Furthermore, the method according to the present invention may comprisethe additional step of longitudinally compressing the third mineralfiber web produced in step e) and additionally or alternatively theadditional step of transversally compressing the third mineral fiber webproduced in step e).

By performing one or more of the above-described compression steps, themineral fiber web exposed to the compression step or steps is made morehomogeneous, resulting in an overall improvement of the mechanicalperformance as compared to a non-compressed mineral fiber web.

According to the presently preferred embodiment of the method accordingto the present invention, the folding of the second mineral fiber web ofstep e) advantageously comprises the step of producing undulationsextending perpendicular to the second longitudinal direction andparallel with the second transversal direction. As the second mineralfiber web is folded in accordance with the teachings of the presentinvention, the segments of the second mineral fiber web are arrangedgenerally perpendicular to the second longitudinal direction andgenerally parallel with the second transversal direction. Consequently,the mineral fibers of the second mineral fiber web are predominantlyarranged in a pattern of crossings providing on the one hand a finalmineral fiber plate of high mechanical strength and on the other hand afinal mineral fiber plate of high insulating capability.

According to a further, additional or alternative embodiment of themethod according to the present invention, the method further comprisesthe following steps substituting step g):

h) producing a fourth non-woven mineral fiber web defining a thirdlongitudinal direction parallel with the fourth mineral fiber web, thefourth mineral fiber web containing mineral fibers and including asecond curable bonding agent, the fourth mineral fiber web being amineral fiber web of a higher compactness as compared to the thirdmineral fiber web,

i) adjoining the fourth mineral fiber web to the third mineral fiber webin facial contact therewith for producing a fifth composite mineralfiber web, and

j) curing the first and second curable bonding agents so as to cause themineral fibers of the fifth composite mineral fiber web to bond to oneanother, thereby forming the cured non-woven mineral fiber web.

The fourth non-woven mineral fiber web which is adjoined to the thirdmineral fiber web in step c) may constitute a separate mineral fiberweb. Thus, the third and the fourth mineral fiber webs may be producedby separate production lines which are joined together in step i).

In accordance with a first embodiment of the method according to thepresent invention, the fourth mineral fiber web is produced byseparating a separate layer of the first mineral fiber web therefrom andby compacting the separate layer for producing the fourth mineral fiberweb.

In accordance with a second embodiment of the method according to thepresent invention, the fourth mineral fiber web is produced byseparating a separate layer of the second mineral fiber web therefromand by compacting the separate layer for producing the fourth mineralfiber web.

In accordance with a third embodiment of the method according to thepresent invention the fourth mineral fiber web is produced by separatinga separate layer of the third mineral fiber web therefrom and bycompacting the separate layer for producing the fourth mineral fiberweb.

The separate layer from which the fourth non-woven mineral fiber web isproduced may irrespective of the origin of the separate layer beseparated from the mineral fiber web being the first, the second or thethird mineral fiber web from which the separate layer is separated as asurface layer or a side segment layer. Furthermore, provided theseparate layer constitute a surface layer, the surface layer may beproduced as a top or a bottom surface layer separated from the mineralfiber web from which the separate layer is separated.

The fourth mineral fiber web may additionally be produced by compactinghe separate layer comprising the step of folding the separate layer soas to produce the fourth mineral fiber web containing mineral fiberspredominantly arranged generally transversely relative to the thirdlongitudinal direction of the fourth mineral fiber web.

The method according to the present invention preferably furthercomprises the additional step similar to the step h) of producing asixth non-woven mineral fiber web similar to the fourth mineral fiberweb, and the step of adjoining in step i) the sixth mineral fiber web tothe third mineral fiber web in facial contact therewith and so as tosandwich the third mineral fiber web between the fourth and sixthmineral fiber web in the fifth composite mineral fiber web. By producinga sixth non-woven mineral fiber web an integral composite mineral fiberstructure of the fourth mineral fiber web is accomplished in whichstructure, the central body originating from the second mineral fiberweb is sandwiched between opposite compacted surface layers constitutedby the fourth and the sixth mineral fiber webs.

The third longitudinal direction defined by the fourth non-woven mineralfiber web may in accordance with alternative embodiments beperpendicular to the second longitudinal direction or identical to thesecond longitudinal direction. Furthermore, the third longitudinaldirection defined by the fourth non-woven mineral fiber web mayconstitute a direction diverging from the above directions andconstitute a direction which is transverse relative to the secondlongitudinal direction.

The method according to the present invention may further preferablycomprise the additional step of compressing the fifth composite mineralfiber web prior to curing the fifth composite mineral fiber web in stepj). The compression of the fifth composite mineral fiber web maycomprise height compression, longitudinal compression and/or transversalcompression. By compressing the fifth composite mineral fiber web, thehomogeneity of the final product is believed to be improved as thecompressing of the fifth composite mineral fiber web produces ahomogenizing effect on the third non-woven mineral fiber webconstituting a central body of the fifth composite mineral fiber web.

According to a particular, relevant embodiment of the method accordingto the present invention, the method further comprises the followingsteps prior to step e):

k) producing a seventh non-woven mineral fiber web defining a fourthlongitudinal direction parallel with the seventh mineral fiber web, theseventh mineral fiber web containing mineral fibers and including athird curable bonding agent, the seventh mineral fiber web being amineral fiber web of a higher compactness as compared to the secondmineral fiber web, and

l) adjoining the seventh mineral fiber web to the second mineral fiberweb produced in step c) in facial contact therewith, prior to step e),for producing an eighth composite mineral fiber web to be folded in stepe) for producing the third non-woven mineral fiber web, and step g) alsoincluding curing the third curable bonding agent.

According to the above-defined embodiment of the method according to thepresent invention, an integral composite product is produced as theseventh mineral fiber web is adjoined to the second mineral fiber webprior to the processing of the eighth composite mineral fiber web instep e) for producing the third non-woven mineral fiber web containingmineral fibers predominantly arranged or orientated in the crossingstructure characteristic of the present invention.

The seventh non-woven mineral fiber web, which is adjoined to the secondmineral fiber web in step 1), may constitute a separate mineral fiberweb. Thus the second and seventh mineral fiber webs may be produced onseparate production lines which are joined together in step 1).

In accordance with a further embodiment of the method according to thepresent invention, the seventh non-woven mineral fiber web is producedby separating a separate layer of the first mineral fiber web therefromand by compacting the separate layer for producing the seventh mineralfiber web.

In accordance with an alternative embodiment of the method according tothe present invention, the seventh mineral fiber web is produced byseparating a separate layer of the second mineral fiber web therefromand by compacting the separate layer for producing the seventh mineralfiber web.

Like the above-described fourth non-woven mineral fiber web, the seventhnon-woven mineral fiber web may, provided the seventh non-woven mineralfiber web is produced by separating a separate layer from the first orsecond mineral fiber web, be produced as a surface layer or a sidesegment layer. Furthermore the surface layer may, provided the separatelayer from which the seventh mineral fiber web is produced is providedas a surface layer of the first or second mineral fiber web, be producedas a top or bottom surface layer separated from the mineral fiber webfrom which the separate layer is separated.

The compacting of the separate layer from which the seventh mineralfiber web is produced may, according to a further embodiment of themethod according to the present invention, comprise the step of foldingthe separate layers so as to produce the seventh mineral fiber webcontaining mineral fibers predominantly arranged generally transverselyrelative to the fourth longitudinal direction of the seventh mineralfiber web.

The method according to the present invention may further preferably andadvantageously comprise the step of applying a covering to a sidesurface or both side surfaces of the third mineral fiber web and/orapplying a covering to a side surface or both side surfaces of the fifthcomposite mineral fiber web. Furthermore, a covering may be applied tothe seventh non-woven mineral fiber web prior to the step 1) ofadjoining the seventh mineral fiber web to the second mineral fiber web,providing a composite eighth mineral fiber web including a coveringapplied to a top or a bottom surface thereof or interlayered between theseventh and second mineral fiber webs of the eighth composite mineralfiber web. The covering constituting an integral component of the eighthcomposite mineral fiber web is, of course, also folded in step e) andproduces interlayered coverings within the structure of the thirdnon-woven mineral fiber web. The covering may be a foil of a plasticsmaterial, such as a continuous foil, a woven or non-woven mesh, oralternatively a foil of a non-plastics material, such as a paper orcloth material, a metal sheet, a metal plate, a metal foil, or a mesh ofmetal wire or wires. The mineral fiber-insulating web produced inaccordance with the method according to the present invention may, asdiscussed above, be provided with two oppositely arranged mineral fiberwebs sandwiching a central body of the composite mineralfiber-insulating web. Provided the mineral fiber-insulating web isproduced as a three-layer assembly, one or both outer side surfaces maybe provided with similar or identical surface coverings.

The step g) of curing the first curable bonding agent and optionally thesecond and third curable bonding agents as well may, dependent on thenature of the curable bonding agent or agents, be carried out innumerous different ways, e.g. by simply exposing the curable bondingagent or agents to a curing gas or a curing atmosphere, such as theatmosphere, by exposing the curable bonding agent or agents toradiation, such as UV radiation or IR radiation. Provided the curablebonding agent or agents are a heat-curable bonding agents, such asconventional resin-based bonding agents normally used within the mineralfiber industry, the process of curing the curable bonding agent oragents includes the step of introducing the mineral fiber web to becured into a curing oven. Consequently, the curing process is performedby means of a curing oven. Further alternative curing appliances maycomprise IR radiators, microwave radiators, etc.

From the cured mineral fiber-insulating web, plate segments arepreferably cut by cutting the cured non-woven third or fifth compositemineral fiber web into plate segment in a separate production step.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is furthermoreobtained by means of a plant for producing a cured non-woven mineralfiber web, comprising:

a) first means for producing a first non-woven mineral fiber webdefining a first longitudinal direction parallel with the first mineralfiber web and a first transversal direction parallel with the firstmineral fiber web, the first mineral fiber web containing mineral fiberspredominantly arranged generally in the first longitudinal directionthereof and including a first curable bonding agent,

b) second means for moving the first mineral fiber web in the firstlongitudinal direction,

c) third means for arranging segments of the first mineral fiber web inpartly mutually overlapping relationship transversely relative to thefirst longitudinal direction and the first transversal direction so asto produce a second non-woven mineral fiber web, the second mineralfiber web defining a second longitudinal direction and a secondtransversal direction and containing mineral fibers predominantlyarranged generally transversely relative to the second longitudinaldirection and the second transversal direction and generallytransversely relative to one another,

d) fourth means for moving the second mineral fiber web in the secondlongitudinal direction,

e) fifth means for folding the second mineral fiber web transverselyrelative to the second longitudinal direction and parallel with thesecond transversal direction so as to produce a third non-woven mineralfiber web, the third mineral fiber web containing mineral fiberspredominantly arranged generally transversely relative to one anotherand generally transversely relative to the second longitudinal directionand the second transversal direction,

f) sixth means for moving the third non-woven mineral fiber web in thesecond longitudinal direction, and

g) seventh means for curing the first curable bonding agent so as tocause the mineral fibers of the third mineral fiber web to bond to oneanother, thereby forming the cured non-woven mineral fiber web.

The plant according to the present invention may advantageously compriseany of the above characteristics of the method according to the presentinvention.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is furthermoreobtained by means of a mineral fiber plate according to the presentinvention, which mineral fiber defines a first direction and comprises:

first and second lamellae arranged transversely relative to the firstdirection, the first and second lamellae containing mineral fiberspredominantly arranged transversely relative to the first direction andtransversely relative to one another, and

the fibers of the first and second lamellae being bonded together in anintegral structure solely through hardened bonding agents hardened in asingle hardening process and initially present in uncured, non-wovenmineral fiber webs from which the first and second lamellae areproduced.

The first and second lamellae of the mineral fiber plate according tothe present invention may be bonded together through an adhesive whichis applied to the outer surfaces of the first and second lamellae afterthe curing and hardening of the bonding agents bonding the mineralfibers of the first and second lamellae together and after cutting thefirst and second lamellae from a cured mineral fiber web produced inaccordance with the teachings of the present invention. The first andsecond lamellae of the mineral fiber web according to the presentinvention may alternatively be linked together through other elementssuch as different mineral fiber products, foils, films or the like.

According to the presently preferred embodiment of the mineral fiberplate according to the present invention, the first and second lamellaeare bonded together through hardened bonding agents hardened in a singlehardening process and initially present in uncured, non-woven mineralfiber webs from which the first and second lamellae are produced.

According to the presently preferred embodiment of the mineral fiberplate according to the present invention described above, the mineralfiber plate is as a unitary structure hardened in a single hardeningprocess through one or more bonding agents present in the mineral fiberwebs from which the lamellae of the mineral fiber plate are composed andfurther optionally applied to surfaces of a adjacent lamellae whichsurfaces are adjoined one another prior to the curing or hardeningprocess.

According to a particular, advantageous embodiment of the mineral fiberplate according to the present invention, the first and second lamellaeare interconnected through mineral fiber layers of a higher mineralfiber compactness as compared to the lamellae. The mineral fiber layersof higher mineral fiber compactness may include mineral fibers arrangedor orientated predominantly along any arbitrary direction independent ofthe crossing-structure arrangement of the mineral fibers of the firstand second lamellae.

According to a further embodiment of the mineral fiber plate accordingto the present invention, a surface layer is applied to one side of thefirst and second lamellae or opposite surface layers of a similarstructure, sandwiching the first and second lamellae in the integralstructure.

The mineral fiber plate according to the present invention mayadvantageously comprise any of the above characteristics of the methodaccording to the present invention and also any characteristics of theplant according to the present invention.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is furthermoreobtained by means of a method of packaging a mineral fiber plate in apackage, comprising the following steps:

providing the mineral fiber plate defining a first direction and beingcompactable along the first direction,

providing the package,

arranging the mineral fiber plate within the package,

compacting the mineral fiber plate along the first direction thereof forsubstantially reducing the overall volume of the mineral fiber plate,e.g. to 30-95%, such as 30-85%, preferably 40-60%, of the overall volumeof the non-compacted mineral fiber plates, and

sealing the package for providing a sealed package within which themineral fiber plate is kept in a compacted state in which the overallvolume of the mineral fiber plate constitutes 30-100%, such as 50-90%,preferably 60-80% of the overall volume of the non-compacted mineralfiber plate.

The high compressibility and compactability of the mineral fiber plateaccording to the present invention and further the capability of themineral fiber plate according to the present invention to recover tosubstantially 100% after the mineral fiber plate has been compacted foreven an elongated period of time renders it possible to package themineral fiber plate exhibiting compressibility and compactability alonga specific direction defined as the first direction of the mineral fiberplates for reducing the overall volume of the mineral fiber plateincluded in the package.

The mineral fiber plate to be packed in accordance with the method ofpackaging a mineral fiber plate in accordance with the present inventionmay constitute any mineral fiber plate exhibiting the characteristicproperty of being compactable along the first direction of the mineralfiber plate which first direction may constitute the longitudinaldirection of the mineral fiber plate or the transversal direction of themineral fiber plate, i.e. the transversal direction defining togetherwith the longitudinal direction the major surface of the mineral fiberplate. It is to be understood that the compressability andcompactability of the mineral fiber plate is a substantially uniformcharacteristic allowing any volume of the mineral fiber plate along thefirst direction to be compacted. Examples of mineral fiber platesexhibiting the above characteristic, i.e. exhibiting compressibility andcompactability along a specific direction defined as the first directionof the mineral fiber plate are mineral fiber plates produced inaccordance with the method according to the present invention ofproducing a cured non-woven mineral fiber web, mineral fiber platesproduced in accordance with the technique described in Applicant'spublished international patent applications, application No.PCT/DK94/00027, publication No. WO 94/16162; application No.PCT/DK94/00028, publication No. WO 94/16163; and application.No.PCT/DK94/00029, publication No. WO 94/16164, to which reference is made,mineral fiber plates produced from mineral fiber webs which have beenexposed to longitudinal compression and produced from an initial uncurednon-woven mineral fiber web or from an uncured non-woven mineral fiberweb which is produced from the initial uncured, non-woven mineral fiberweb through positioning the initial uncured non-woven mineral fiber webin overlaying relationship.

According to the presently preferred embodiment of the method ofpackaging a mineral fiber plate, a plurality of mineral fiber plates arepacked together, and the method comprises packaging a plurality ofmineral fiber plates each defining a respective first direction, and thestep of arranging the mineral fiber plate within the package includingarranging the plurality of mineral fiber plates within the package so asto arrange the mineral fiber plates of the plurality in mutuallyparallel relationship and having the respective first directions of themineral fiber plates positioned parallel to one another.

The package within which the compacted mineral fiber plate or plates arecontained may be constituted by any appropriate package such as acardboard package, or preferably a light weight package constituted by acovering of a plastic foil which is sealable, preferably heat sealableand which is wrapped around the compacted mineral fiber plate or platesand sealed in the wrapped-around-state providing the package withinwhich the mineral fiber plate or plates are enclosed or sealed.

The number of mineral fiber plates within the plurality of mineral fiberplates contained within the package may vary from a very few numberssuch as 2-4 to a fairly large number such as 20-30 or even more mineralfiber plates. The mineral fiber plate which is sealed within the packageaccording to the method of packaging a mineral fiber plate preferablyconstitutes a mineral fiber plate having any of the characteristics ofthe mineral fiber plate according to the present invention.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is furthermoreobtained by means of a package containing a mineral fiber plate,comprising:

the mineral fiber plate defining a first direction and being compactablealong the first direction,

the package constituting a sealed package within which the mineral fiberplate is confined, and

the mineral fiber plate being kept in a compacted state within thesealed package in which state the overall volume of the mineral fiberplate is substantially reduced, e.g. to 30-100%, such as 50-90%,preferably 60-80% of the overall volume of the non-compacted mineralfiber plate through compacting the mineral fiber plate along the firstdirection thereof.

The package according to the present invention is preferably produced inaccordance with the method of packaging a mineral fiber plate andfurther preferably comprises a mineral fiber plate exhibiting any of thecharacteristics of the mineral fiber plate according to the presentinvention.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is further obtainedby means of a method of producing a tubular insulating element,comprising sing the following steps:

a) providing a non-woven mineral fiber web defining a first longitudinaldirection parallel with the non-woven mineral fiber web, a firsttransversal direction parallel with the non-woven mineral fiber web, anda second transversal direction perpendicular to the first longitudinaland transversal directions, and

b) cutting the tubular insulating element from the non-woven mineralfiber web defining a second longitudinal direction, the secondlongitudinal direction being parallel with the first longitudinaldirection, the first transversal direction, or the second transversaldirection or defining a specific angular relationship with the firstlongitudinal direction, the first transversal direction or the secondtransversal direction.

According to the method of producing a tubular insulating elementaccording to the present invention, the inherent characteristics of thebasic non-woven mineral fiber web from which the tubular insulatingelement is produced may be transferred to the tubular insulatingelement. More particularly, a tubular insulating element may be producedexhibiting a specific characteristic along a specific direction of thetubular insulating element such as exhibiting compressibility andcompactability along a specific direction as the tubular insulatingelement is produced from a non-woven mineral fiber web exhibiting thecharacteristic in question, e.g. the compressability and compactabilityalong a specific direction of the non-woven mineral fiber web whichspecific direction is orientated along the intentional specificdirection of the tubular insulating element. The specific direction ofthe non-woven mineral fiber web may constitute the first longitudinaldirection, the first transversal direction or the second transversaldirection or may diverge from any of these directions.

The non-woven mineral fiber web from which the tubular insulatingelement is produced may in accordance with the teachings of the presentinvention constitute a single non-woven mineral fiber web oralternatively a non-woven mineral fiber web assembly composed of aplurality of individual non-woven mineral fiber web segments eachexhibiting specific characteristics which are transferred to the tubularinsulating element.

Preferably, and advantageously, the non-woven mineral fiber web fromwhich the tubular insulating element is produced in accordance with themethod according to the present invention is produced in accordance withthe method of producing a cured non-woven mineral fiber web according tothe present invention. Alternatively, the non-woven mineral fiber webfrom which the tubular insulating element is produced may be producedfrom a basic, uncured non-woven mineral fiber web and being exposed tocompression along the first longitudinal direction and/or along thefirst transversal direction and/or the second transversal directionprior to and/or after curing the uncured non-woven mineral fiber web.For producing a tubular insulating element having an outer surfacecoating, the method of producing the tubular insulating elementaccording to the present invention preferably also comprises the step:

c) applying an outer surface coating to the tubular insulating element,the outer surface coating being constituted by a plastics foil, a wovenor non-woven plastics fiber foil, an aluminum foil, an aluminum foilreinforced plastics foil, a fiber reinforced plastics foil, a creapepaper covering, a glassfiber reinforced foil or a combination thereof.

The outer surface coating may in accordance with alternative techniquesbe applied as a contiguous surface coating or as a segmentary outersurface coating. Further alternatively, the outer surface coating may befixated to, e.g. adhered to, the outer surface of the tubular insulatingelement in a continuous surface adhesion or as a spot or blind contactadhesion.

The above objects, the above advantages and the above features togetherwith numerous other objects, advantages and features is further obtainedby means of a tubular insulating element comprising a body containingmineral fibers bonded together in an integral structure through hardenedbonding agents and being produced from a mineral fiber plate defining afirst longitudinal direction parallel with the non-woven mineral fiberweb, a first transverse direction parallel with the non-woven mineralfiber web, and a second transversal direction perpendicular to the firstlongitudinal and transversal directions by cutting the tubularinsulating element from the non-woven mineral fiber web defining asecond longitudinal direction, the second longitudinal direction beingparallel with the first longitudinal direction, the first transversaldirection, or the second transversal direction or defining a specificangular relationship with the first longitudinal direction, the firsttransversal direction or the second transversal direction. The tubularinsulating element according to the present invention is preferablyproduced in accordance with the method of producing a tubular insulatingelement and further preferably comprises any of the characteristics ofthe mineral fiber plate according to the present invention and any ofthe above discussed characteristics obtained by the method of producinga tubular insulating element in accordance with the teachings of thepresent invention.

The present invention will now be further described with reference tothe drawings, in which

FIG. 1 is a schematic and perspective view illustrating a productionplant for the production of a mineral fiber web according to the presentinvention,

FIG. 2 is a schematic and perspective view illustrating in greaterdetails a production step of the production of the mineral fiber webalso illustrated in FIG. 1,

FIG. 3 is a schematic and perspective view similar to the view of FIG. 2illustrating an additional production step of the production of themineral fiber web shown in FIGS. 1 and 2,

FIG. 4a is a schematic and perspective view illustrating a firstembodiment of a process of separating a part of the mineral fiber webtherefrom and further of processing the part of the mineral fiber web,

FIG. 4b is a schematic and perspective view illustrating a second oralternative embodiment of the process also shown in FIG. 4a ofseparating and processing a part of the mineral fiber web,

FIG. 5 is a schematic and perspective view illustrating production stepsof combining separate surface layers produced in accordance with one ofthe production steps shown i FIGS. 4a and 4b and a central mineral fiberweb produced in accordance with the production process shown in FIG. 1,of curing the combined mineral fiber web and of separating the curedmineral fiber web into plate segments,

FIG. 6 is a schematic and perspective view illustrating an initialproduction step of producing a combined mineral fiber web of two layersof different compactness to be processed in the production plant shownin FIG. 1 in accordance with the teachings of the present invention,

FIG. 7 is a schematic and perspective view illustrating alternativeproduction steps of separating the cured mineral fiber web into a totalof four separate mineral fiber webs to be further processed through theapplication of surface layers to the outer surfaces of the four separatemineral fiber webs,

FIG. 8 is a schematic, sectional and perspective view of a firstembodiment of a mineral fiber plate segment produced in accordance withthe teachings of the present invention,

FIG. 9 is a schematic, sectional and perspective view of a secondembodiment of a mineral fiber product produced in accordance with theteachings of the present invention,

FIG. 10 is a schematic, sectional and perspective view of a thirdembodiment of a mineral fiber product produced in accordance with theteachings of the present invention,

FIG. 11 is a schematic, sectional and perspective view of a fourthembodiment of a mineral fiber product produced in accordance with theteachings of the present invention,

FIG. 12 is a schematic, sectional and perspective view of a fifthembodiment of a mineral fiber product produced in accordance with theteachings of the present invention and of a structure similar to thestructure of the fourth embodiment shown in FIG. 11,

FIG. 13 is a schematic, sectional and perspective view of a sixthembodiment of a mineral fiber product constituting a mineral fiber platesegment,

FIG. 14 is a schematic, sectional and perspective view of a seventhembodiment of a mineral fiber plate segment produced in accordance withthe teachings of the present invention,

FIG. 15 is a schematic, sectional and perspective view illustrating anadvantageous property of the mineral fiber product constituting amineral fiber plate segment produced in accordance with the teachings ofthe present invention,

FIG. 16 is a schematic, sectional and perspective view of an eighthembodiment of a mineral fiber product produced in accordance with theteachings of the present invention,

FIGS. 17a and 17b are diagrammatic views illustrating the fireresistance characteristics of mineral fiber plate products produced inaccordance with the teachings of the present invention as compared toconventional mineral fiber plate products, and

FIGS. 18a and 18b are schematic and perspective views illustrating atechnique of packaging mineral fiber plates according to the presentinvention in a highly compressed and compacted state,

FIG. 19 is a schematic and perspective view illustrating a packagingplant for the packaging of mineral fiber plates according to the presentinvention in a highly compressed and compacted state,

FIG. 20 is a schematic and perspective view similar to the view of FIG.18b illustrating a package containing mineral fiber plates produced inaccordance with the technique illustrated in FIG. 19,

FIG. 21 is a schematic and a perspective view of a set of mineral fiberplates according to the present invention from which tubular insulatingelements are produced of various configurations and exhibiting a highdegree of flexible capability,

FIG. 22 is a schematic and perspective view of a tubular insulatingelement produced in accordance with the technique disclosed in FIG. 21and illustrating the high flexibility of the tubular insulating element,

FIG. 23 is a schematic and perspective view similar to the view of FIG.21 of a set of mineral fiber plates from which tubular insulatingelements are produced in various configurations, and

FIG. 24 is a schematic and perspective view similar to the view of FIG.22 illustrating a tubular insulating element produced in accordance withthe technique illustrated in FIG. 23.

In the upper left hand part of FIG. 1, a first station for carrying outa first step of producing a mineral fiber web is disclosed. The firststep involves the formation of mineral fibers from a mineral fiberforming melt which is produced in a furnace 10 and which is supplied toa spout 12 of the furnace 10 to one or more rapidly rotating spinningwheels 14 to which the mineral fiber forming web is supplied as amineral fiber forming melt stream 16. As a mineral fiber forming meltstream 16 is supplied to the spinning wheel or wheels 14 in a radialdirection relative thereto, a cooling gas stream is simultaneouslysupplied to the rapidly rotating spinning wheel or wheels 14 in theaxial direction thereof causing the formation of individual mineralfibers which are expelled or sprayed from the rotating spinning wheel orwheels 14 as indicated by the reference numeral 18. The mineral fiberspray 18 is collected on a continuously operated first conveyor belt 22and forms a primary mineral fiber web 20 which is transferred from thefirst conveyor belt 22 to a second conveyor belt 24. A heat hardening orheat curable bonding agent is also added to the primary mineral fiberweb 20 either directly thereto or at the stage of expelling the mineralfibers from the spinning wheel or wheels 14, i.e. at the stage offorming the individual mineral fibers 18. The first conveyor belt 22 issloping relative to the horizontal direction and relative to the secondconveyor belt 24 which is arranged substantially horizontally. The firstconveyor belt 22 constitutes a collector conveyor belt, whereas thesecond conveyor belt 24 constitutes a transport conveyor belt.

From the second conveyor belt 24, the primary mineral fiber web 20 istransferred to a second station designated the reference numeral 26 inits entirety. The station 26 constitutes a station in which the overalldirection of transportation of the primary mineral fiber web 20 istransformed from the longitudinal direction defined by the first andsecond conveyor belts 22 and 24, respectively, to a longitudinaldirection determined by a mineral fiber web 30. The mineral fiber web 30constitutes a mineral fiber web from which the mineral fiber productsare produced in accordance with the teachings of the present inventionas will be evident from the below description. The mineral fiber web 30is a mineral fiber web originating from a directly collected primarymineral fiber web 20 and consequently contains mineral fiberspredominantly arranged or orientated in the longitudinal direction ofthe mineral fiber web 30. Thus, the mineral fiber web 30 defines a firstlongitudinal direction and a first transversal direction, the firstlongitudinal direction being the direction along which the mineralfibers of the mineral fiber web 30 is predominantly arranged ororientated.

The mineral fiber web 30 is transferred from the station 26 by means ofconveyor belts, not shown in FIG. 1, to a roller 28 which serves thepurpose of shifting the direction of transportation of the mineral fiberweb 30 from a substantially horizontal direction to a substantiallyvertical direction as indicated by an arrow 36 for the transfer of themineral fiber web 30 to a further station in which the mineral fiber web30 is transformed into a segmentary mineral fiber web 50 by arrangingsegments of the mineral fiber web 30 in partly mutually overlappingrelationship and transversely relative to the longitudinal direction andthe transversal direction of the segmentary mineral fiber web 50 for theformation of the segmentary mineral fiber web 50. The transformation ofthe mineral fiber web 30 into the segmentary mineral fiber web 50 isaccomplished by means of two pendulum or oscillating conveyor belts 32and 34 having upper input ends to which the mineral fiber web 30 isinput and lower horizontally oscillating output ends from which themineral fiber web 30 is output constituting segments which are arrangedin the above-described partly overlapping relationship for the formationof the segmentary mineral fiber web 50.

In FIG. 1, two segments designated the reference numerals 38 and 40,respectively, are shown constituting segments of which the segmentarymineral fiber web 50 is composed. The segment 40 is defined by oppositefolds 44 and 46 connecting the segment 40 to a previously producedsegment and to the segment 38, respectively. The segment 38 is furtherdefined by a fold 48 through which the segment is connected to themineral fiber web 30 extending substantially vertically to the pendulumconveyors 32 and 34. The segmentary mineral fiber web 50 is moved from aposition below the pendulum conveyor belts 32 and 34 to the right inFIG. 1 towards a further processing station 56 comprising two heightcompressing or compacting conveyor belts 52 and 54 which serve thepurpose of compacting and homogenizing the segmentary mineral fiber web50. In FIG. 1, the reference numeral 42 designates a front edge of thesegment 38 which front edge constitutes a boundary line between thesegments 38 and 40 of the segmentary mineral fiber web 50.

It is to be realized that the segmentary mineral fiber web 50 iscomposed of segments originating from the mineral fiber web 30 in whichthe mineral fibers are predominantly arranged or orientated along thelongitudinal direction of the mineral fiber web 30 and the mineralfibers of the segmentary mineral fiber web 50 is consequentlypredominantly arranged or orientated in directions determined by theposition of the individual segments of the segmentary mineral fiber web50 such as the segments 38 and 40. Thus, the segments 38 and 40 containmineral fibers which are predominantly arranged tranversely relative tothe longitudinal direction of the segmentary mineral fiber web 50 andtransversely relative to one another. The transverse directions alongwhich the mineral fibers of the segmentary mineral fiber web 50 arearranged is basically defined by the ratio between the speed oftransportation of the mineral fiber web 30 and the speed oftransportation of the segmentary mineral fiber web 50, i.e. the ratiobetween the speed of transportation of the conveyor belt by means ofwhich the mineral fiber web 30 is fed to the pendulum conveyors 32 and34 and the speed of transportation of the conveyor belt by means ofwhich the segmentary mineral fiber web is transferred from the pendulumconveyor belts 32 and 34 towards the station 56. Through the alternationof the ration between the above described speeds of transportation ofthe mineral fiber 30 and the segmentary mineral fiber web 50, the partlymutually overlapping relationship of the segments of the segmentarymineral fiber web 50 is adjustable and also the overall orientation ofthe mineral fibers of the segmentary mineral fiber web 50 along thetransverse directions along which the mineral fibers of the segmentarymineral fiber web 50 are predominantly arranged or orientated.

The conveyor belts 52 and 54 of the height compressing or compactingstation 56 are of a wedge-shaped configuration providing a compressionof the segmentary mineral fiber web 50 at least at the output end of thecompacting station 56 and are operated so as to cause a verticalpendulum motion of the segmentary mineral fiber web 50 at the output endof the compacting station 56. Consequently, the compacting station 56causes an overall homogenization through rearrangement of mineral fibersproducing a homogene mineral fiber web which is output from thecompacting station 56 in a vertical pendulum motion to a furtherprocessing station 64 in which the mineral fiber web is furtherprocessed for the formation of a folded mineral fiber web.

In the processing station 64, the mineral fiber web output from thecompacting station 56 is folded for the formation of a mineral fiber webin which the mineral fiber web output from the compacting station 56 isfolded vertically and consequently transversally or perpendicularlyrelative to the longitudinal direction of the mineral fiber web andparallel with the transversal direction of the mineral fiber web. Thefolded mineral fiber web is produced by means of two conveyor belts 58and 62 sandwiching the mineral fiber web and providing a furtherdeceleration of the rate of transportation of the mineral fiber web intothe compacting station and consequently a vertical folding of themineral fiber web.

From the station 64, the vertically folded mineral fiber web is input toa further station 72 comprising two conveyor belts 66 and 68 whichfurther decelerates the speed of transportation of the folded mineralfiber web 60 for the formation of a compacted and homogenized foldedmineral fiber web 70. The mineral fiber web 70 constitutes a finalproduct which may further be processed as will be described below forthe formation of the specific mineral fiber products such as insulatingplates or composite products.

In FIG. 2, the segmentary mineral fiber web 50 is shown in greaterdetails illustrating the segments 38 and 40 and further the edges 46 and48. FIG. 2 further illustrates in greater details the predominantarrangement or orientation of the mineral fibers of the individualsegments of which the segmentary mineral fiber web 50 is composed.

In FIG. 3, the folded mineral fiber web 60 and further the compacted andhomogenized folded mineral fiber web 70 are shown illustrating thestructure of the webs. In the lower right hand part of FIG. 3, twolamellae or segments of the mineral fiber web 70 are shown designatedthe reference numerals 74 and 80. The lamella or segment 74 furtherdiscloses two subsegments 76 and 78 which are interconnected through aline of separation designated the reference numeral 77. The line 77originates from an edge such as the edge 42 shown in FIGS. 1 and 2 ofthe arrangement of the segments such as the segments 38 and 40 of whichthe segmentary mineral fiber web 50 are composed in the partly mutuallyoverlapping relationship in which the segments are positioned. Thus, inFIG. 3, the subsegments 76 and 78 contain mineral fibers which arepredominantly arranged or orientated in transverse directions relativeto the longitudinal and transversal directions of the mineral fiber web70 and further relative to one another. In FIG. 3, the reference numeral84 designates an arrow representing the longitudinal direction of themineral fiber web 70. Similarly, the reference numerals 83 and 85designate arrows representing the transversal direction and theelevational direction, respectively, of the mineral fiber web 70. In thebelow description, the expression "the longitudinal direction" refers tothe direction indicated by the arrow 84 in FIG. 3 rather than a specificorientation or direction of a product relating to the geometricalrelations of the product. Thus, the expression "the longitudinaldirection" refers to any direction coinciding with the directionindicated by the arrow 84 shown in FIG. 3 and referring to the directionperpendicular to the direction of folding the web and furtherperpendicular to the folds of the folded product. Similarly, in thebelow description, the expression "the transversal direction" refers toa direction along the folds of the product and the expression "theelevational direction" refers to a direction perpendicular to thelongitudinal direction and the transversal direction rather than avertical direction in relation to the gravitational field. Thus, theelevational direction refers to the direction along which the folds ofthe product are produced. It is to be emphasized that the above threedirections, i.e. the longitudinal direction, the transversal directionand the elevational direction of any product according to the presentinvention refer to the geometrical relations of the folds of theproducts rather than the orientation relative to horizontal and verticaldirections as referring to the gravitational field.

FIG. 3 further illustrates a specific characteristic of the mineralfiber web 70 as the line 77 separating the subsegments 76 and 78 fromone another are shifted from the segment 78 to the segment 80 andfurther to the adjacent segments basically determined by the ratio ofoverlapping ratio of the segmentary mineral fiber web 50 such as thesegments 38 and 40 and the height of the foldings of the folded andcompacted mineral fiber web 70 such as the segments 74 and 80. It is tobe realized that the indication of the predominant orientation of themineral fibers of the mineral fiber webs described above is somewhatexaggerated for illustrative purposes exclusively. In a specificproduct, the predominant orientation of the mineral fibers of thesegments of the product may be less distinct as compared to the views ofthe drawings.

In FIGS. 4a and 4b, additional or supplementary processing steps aredisclosed. In FIG. 4a, the mineral fiber web 30 is shown in the upperpart of FIG. 4a and is transported towards a rotating circular knife 86by means of which a segment layer 88 is separated from the mineral fiberweb 30. The segment layer is moved past a propeller roller and along twosloping conveyor belts 92 and 94 serving the purpose of arrangingsegments of the segment layer 88 in partly mutually overlappingrelationship for the formation of a transversely folded mineral fiberweb 100 similar to the web 50 described above with reference to FIG. 1.In FIG. 4a, a segment of the transversely folded mineral fiber web 100is defined between two outer folds 96 and 98 of the mineral fiber web.The segmentary mineral fiber web 100 is input to a compacting andhomogenizing station 102 which differs from the compacting station 56described below as the compacting station 102 comprises a plurality ofrollers which serve the purpose of height compressing the mineral fiberweb which is moved through the compacting and homogenizing station 102.From the compacting and homogenizing station 102, a compact andhomogenized mineral fiber web 104 is output and moved into contact witha further circular rotating knife 106 which separates the mineral fiberweb 104 into two substantially identical mineral fiber webs designatedthe reference numeral 108 and 110 which are moved past additionalrollers 112 and 114 for transferring the mineral fiber webs 108 and 110to a further processing station to be described below with reference toFIG. 5.

In FIG. 5, the folded and compacted mineral fiber web 70 produced asdescribed above with reference to FIG. 1, is brought into contact withthe mineral feber webs 108 and 110 which are produced as described abovewith reference to FIG. 4a. The mineral fiber webs 108 and 110 areapplied to opposite side surfaces of the folded and compacted mineralfiber web 70 by means of two pressure rollers 134 and 136 which forcethe mineral fiber webs 108, 70 and 110 into intimate contact with oneanother optionally through the application of additional adhesivematerial such as additional bonding or curing agents which are appliedto the surfaces of the mineral fiber webs 108 and 110 and/or the outerside surfaces of the folded and compacted mineral fiber web 70 which arebrought into contact with one another. Through the contacting of themineral fiber webs 108 and 110 to the folded and compacted mineral fiberweb 70, a composite mineral fiber web 140 is produced which is thereuponintroduced into a curing oven section 141 shown in the central part ofFIG. 5 and comprising two curing oven parts 142 and 143 which arepositioned above and below the composite mineral fiber web 140,respectively.

From the curing oven section 141, a cured composite mineral fiber web150 is output and moved to a further station in which a cutting knife144 separates the cured composite mineral fiber web 100 into separatemineral plate segments which are thereupon moved from the productionplant for storage, further processing or packaging. In FIG. 5, a mineralfiber plate product produced by separating the product from the curedcomposite segmentary mineral fiber webs 50 is designated the referencenumeral 146. The composite mineral fiber plate product 146 comprises acentral core 148 and opposite surface layers 147 and 149 and is to bedescribed in greater details below with reference to FIG. 8. It is to berealized that the technique of applying a top and bottom layer to thefolded and compacted mineral fiber web 70 may be amended by deleting oneof the layers such as the top layer or alternatively the bottom layerconstituted by the web 108 and 110, respectively, or by applying e.g. afoil or foils to one or both sides of the folded and compacted mineralfiber web 70.

In FIG. 4b, an alternative technique of producing a separate mineralfiber web to be used for the formation of a top or bottom layer of thefinal composite mineral fiber product is disclosed differing from thetechnique disclosed in FIG. 4a in that a top surface layer 118 isseparated from the initial mineral fiber web 20 which is transported inits longitudinal direction thereof and which is input to a horizontallyand transversally operated cutting belt or knife 121. The initialmineral fiber web 20 is transported to the belt or knife 121 by means ofa conveyor belt 121. The belt or knife 121 divides the input mineralfiber web 20 into a top layer 118 and a major part from which themineral fiber web 30 is produced. The top layer is moved from the beltor knife 121 by means of a conveyor belt 118 and input to twosandwiching conveyor belts 128 and 132 which serve the purpose ofcompacting or homogenizing the mineral fiber web which is output fromthe sandwiching conveyor belts 128 and 132 and which is designated thereference numeral 130.

The mineral fiber web 130 may constitute a web which is furtherprocessed as described above with reference to FIG. 4a and consequentlyseparated into two parts for the formation of top and bottom layers ofthe final composite mineral fiber product or alternatively be folded,further compacted or homogenized for producing a high strength top andor bottom layer of the final composite mineral fiber product. Themineral fiber web 30 produced from the initial mineral fiber web 20 bythe separation of the top layer 118 therefrom is moved from the belt orknife 121 by means of two conveyor belts 122 and 124 and has itsdirection of transportation shifted e.g. as shown in FIG. 1 by means ofthe station 26 prior to the step of inputting the mineral fiber web 30into the pendulum conveyor belts serving the purpose of arrangingsegments of the mineral fiber web 30 in partly mutually overlappingrelationship as described above with reference to FIG. 1. In FIG. 4b,the pendulum conveyor belt 34 is also shown.

In FIG. 6, a further processing station is shown in which a mineralfiber web 50' originating from the mineral fiber web 50 shown in FIG. 1,however, optionally partly compressed is transferred along a conveyorbelt 153 to a separation station in which a separating assembly 154comprising a movable cutting belt 156 divides the mineral fiber web intotwo separate mineral fiber webs or parts designated the referencenumerals 158 and 160. The part 160 is moved through two sets ofsandwiching conveyor belts comprising a first set 162 and 164 and asecond set 166 and 168 to a collector conveyor belt 170. The first andsecond sets of conveyor belts 162, 164 and 166, 168, respectively, mayproduce a compacting and homogenization of the mineral fiber web 160 asdescribed above. The mineral fiber web 158 is also input to twosandwiching conveyor belts 172 and 174 and further into a compacting andhomogenizing station 176 similar to the station 102 described above withreference to FIG. 4a for producing a compacted mineral fiber web 178which is transferred from the compacting station 176 to the mineralfiber web transferred along the conveyor belt 170 by means of a furtherconveyor belt 180. By means of the conveyor belt 180, the compacted andhomogenized mineral fiber web 178 is positioned on top of the mineralfiber web originating from the mineral fiber web 160 and optionallypartly compacted and homogenized as stated above producing a compositemineral fiber web 182 comprising of a high compacted top layer and asomewhat less compacted bottom layer. The top and bottom layers may beadhered to one another by means of heat curable or hardenable bondingagents originally present in the mineral fiber web 30 or alternativelyby means of a heat curable or hardenable bonding agent constituting anadhesive which is applied to the top and/or bottom layers prior to thestep of contacting the top and bottom layers with one another togetherdefining the composite mineral fiber web 182. In FIG. 6, the separatingassembly 154 may be shifted from the positioned shown in FIG. 6 towardsthe conveyor belt 162 by means of a drive motor not shown in thedrawings in order to alter the thickness of the mineral fiber web 158 ascompared to the thickness of the mineral fiber web 160. In its extremeposition the separating assembly 154 is prevented from separating themineral fiber web 50' into the mineral fiber webs 158 and 160 as themineral fiber web 130 is in its entirety forced into contact with thesandwiching conveyor belts 162 and 164.

In the left hand part of FIG. 7, the above-described curing oven section141 comprising the top and bottom curing oven sections 142 and 143 isshown. In FIG. 7, the mineral fiber web which is output from the curingoven sections 141 is designated the reference numeral 150' as themineral fiber web 150' differs from the cured composite mineral fiberweb 150 described above with reference to FIG. 5 in that the mineralfiber web 150' is produced solely from the folded and compacted mineralfiber web 70 without the addition of the top and bottom layers producedfrom the mineral fiber webs 108 and 110. The cured mineral fiber web150' is input to a wire or belt separator comprising a wire or belt 184which is journalled on two rotatable wheels 186 and 188 which cause thewire or belt 184 to be moved horizontally and transversally relative tothe mineral fiber web 150' causing a separation of the mineral fiber web150' into two parts 192 and 194.

By means of a rotating circular knife 196 similar to the above-describedrotating circular knives 86 and 106, the parts 192 and 194 are furtherdivided into a total of four webs 198, 200, 202 and 204. From tworollers 208 and 210 positioned above the top mineral fiber webs 198 and200, two foils 209 and 211 are applied to the upper surfaces of the topwebs 198 and 200, respectively, and fixated to the top surfaces thereofby means of a sewing mechanism or alternatively by means of an adhesiveas illustrated schematically at 216. After the adhesion of the foils 209and 211 to the top webs 198 and 200, two top surface covered webs 220and 222 are produced which are wound in a spiral configuration as shownschematically in the upper right hand part of FIG. 7.

Similarly, two foils are applied to the lower sides of the bottom webs202 and 204 which foils are supplied from two rolls 212 and 214,respectively, providing two foils one of which is designated thereference numeral 215. The foil 215 is applied to the lower side of theweb 204, whereas the foil applied to the lower side of the web 202 isnot visible in FIG. 7. In a station 218 similar to the station 216described above, the foils supplied from the rolls 212 and 214 arefixated to the lower sides of the webs 202 and 204 for the formation ofcomposite bottom surface covered webs 224 and 226 similar to theabove-described composite webs 220 and 222.

In FIG. 8, a fragmentary and perspective view of the first embodiment ofa mineral fiber plate assembly 146 is shown produced from the mineralfiber web 150 shown in FIG. 5. The mineral fiber plate assembly 146comprising the central core or body 148 is produced from the mineralfiber web 70 shown in FIGS. 1 and 5. The central core or body 148 isproduced from the compacted mineral fiber webs 108 and 110 as describedabove with reference to FIG. 5. The central core or body 148 i s asdescribed above with reference to FIGS. 1-3 composed of a plurality oftransversely positioned segments 228, 230 and 236 which are producedfrom the mineral fiber web 30 shown in FIG. 1 through the arranging ofthe segments such as the segments 38 and 40 of the mineral fiber web 30in partly mutually overlapping relationship through folding of themineral fiber web 30 along a direction transversely relative to thelongitudinal and transversal directions of the segmentary mineral fiberweb 50 produced through the folding process. The segments 228 and 230constitute segments which are arranged perpendicular to the oppositesurface layers 146 and 147 and are connected through a connectionsegment 232. In FIG. 8, a further segment of the central core or body148 is designated the reference numeral 236 and is positioned adjacentto the segment 232 and connected thereto through a connector segment 234similar to the segment 232. The segment 228 further discloses, as isevident from FIG. 8, a structure similar to the structure of thesegments 78 and 80 shown in FIG. 3 and comprises two subsegments 237 and239 which are interconnected through a segment 238 originating from aline similar to the line 77 shown in FIG. 3. The subsections 237 and 239each comprise mineral fibers predominantly arranged or positioned alongrespective directions which are positioned transversely relative to thelongitudinal and transversal directions defined by the mineral fiberassembly 146 and further relative to one another.

The segments 230 and 236 like the other segments of the structure shownin FIG. 3 also includes mineral fibers which in varying subsegments ofthe individual segments include mineral fibers predominantly arranged or30 positioned along the above-described transverse directions. Theoverall structure of the central core or body 148 of the mineral fiberplate assembly 146 provides through the arrangement or positioning ofthe mineral fibers of the individual subsegments such as the subsections237 and 239 a mineral fiber structure comprising mineral fiber structurepredominantly comprising mineral fibers arranged transversely relativeto the main directions, i.e. the longitudinal and transveral directionsof the mineral fiber plate assembly 146 further providing internalmineral fiber crossings within the structure providing on the one handexcellent mechanical characteristics as to mechanical strength andbending properties and on the other hand excellent insulating propertiesas compared to conventional high strength and high insulating mineralfiber plate assemblies, respectively.

In FIG. 9, a second embodiment of a mineral fiber product is showncomprising the above-described central core or body 148 which isprovided with a top surface covering constituted by a covering of acontinuous foil or a mesh 246 made from a plastics material oralternatively a metal mesh material. The central core or body 148 mayapart from the top surface covering 246 be provided with a bottomsurface covering not shown in FIG. 9. The top surface covering 246 maybe applied to the central core or body 248 before or after the curingstation 141 shown in FIG. 5. depending on the properties of the materialof the top surface covering and the ability of the material of the topsurface covering to adhere to the central core or body 148 throughmelting, adhesion, sewing etc.

In FIG. 10, a third embodiment of a mineral fiber product 240 is showncomprising the central core or body 148 described above with referenceto FIG. 8. The central core or body 148 is at opposite side surfacesthereof provided with two surface coverings 242 and 244 which mayconstitute water and air impermeable sealings or alternativelyreinforcing films or foils or further alternatively IR reflecting foilssuch as aluminum foils.

In FIG. 11, a fourth embodiment of a mineral fiber product 250 is showncomprising lamellae 255, 256 and 257 which are produced from the mineralfiber web 70 shown in FIG. 1 and, as discussed above with reference toFIG. 5, cut into individual plate segments which are thereupon turned90° in accordance with the technique described in international patentapplication, international application No. PCT/DK91/00383, internationalpublication No. WO92/10602. The lamellae 255, 256 and 257 are thereuponadhered to intermediate compacted mineral fiber layers 251, 252, 253 and254 for providing a three lamella composite structure shown in FIG. 11.Along cutting lines 258 and 259, the composite structure composed of thelamellae 255, 256 and 257 and the compacted surface layers 251, 252, 253and 254 is divided into separate mineral fiber plates.

In an alternative process of producing the assembly shown in FIG. 11,the lamellae 255, 256 and 257 are adhered to the compacted surfacelayers 251, 252, 253 and 254 prior to the curing of the bonding agentpresent within the webs from which the lamellae 255, 256 and 257 areproduced. In this alternative process, the surface layers 251, 252, 253and 254 are also preferably constituted by uncured compacted mineralfiber containing components which are adhered through an additional heatcurable or hardenable bonding material to the uncured lamellae 255, 256and 257 or alternatively through the uncured bonding agents of thelamellae 255, 256 and 257 and the intermediate uncured mineral fibercomponents 251, 252, 253 and 254. Further alternatively, the assemblyshown in FIG. 11 may be produced from uncured lamellae and previouslycured surface components or alternatively cured lamellae and uncuredsurface components which are thereupon introduced into the curing ovenfor curing the uncured mineral fiber bonding agents and any heat curableor hardenable bonding material used for adhering the lamellae and thesurface layers together.

In FIG. 12, a slightly modified embodiment of the composite structure ofFIG. 11 is shown constituting a fifth embodiment 260 of the mineralfiber product according to the present invention. The fifth embodimentor mineral fiber plate assembly 260 comprises lamellae 262 similar tothe lamellae 255, 256 and 257 described above with reference to FIG. 11.The lamellae 262 are positioned having one of its segments similar tothe segments 228, 230 and 236 of the central core or body 148 positionedin facial contact with a foil 244 which may constitute a supporting foilor a water and air impermeable membrane. Between the lamellae 262,compacted mineral fiber elements 264 and 266 are interposed constitutingreinforcing elements similar to the above-described compacted surfacelayers 251, 252, 253 and 254 of the assembly 250 described above withreference to FIG. 11. The assembly 260 shown in FIG. 12 may be dividedinto separate mineral fiber plate products comprising a single lamella262 or a plurality of lamellae 262.

In FIG. 13, the central core or body 148 of the composite mineral fiberplate product 146 shown in FIGS. 5 and 8 is disclosed in greaterdetails. In FIG. 13, the fiber structure of the lamella or segment 228is shown clearly illustrating that the subsections 237 and 239 comprisemineral fibers which are predominantly arranged along a singletransverse direction relative to the longitudinal, transversal andvertical direction defined by the central core or body 148 whereas thesegment 238 originating from a line of separation corresponding to theline 77 shown i FIG. 3 comprises mineral fibers arranged or orientatedtransversely relative to one another.

In FIG. 14, a seventh embodiment of a mineral fiber plate segment isshown designated the reference numeral 270 in its entirety. The segment270 is composed of a central core or body 274 and a top layer 272. Thetop layer 272 is basically of a structure similar to the structure ofthe bottom and top layers 147 and 149, respectively, of the compositemineral fiber plate 146 shown in FIG. 8. The central core 274 of themineral fiber plate segment 270 is produced from the composite mineralfiber web 182 described above with reference to FIG. 6 and includes acentral filling out designated the reference numeral 276 which is a highcompactness central filling out produced from the compacted andhomogenized mineral fiber web 178 of the composite mineral fiber web182. The part 276 may alternatively be produced from a different basicweb including mineral fibers arranged or positioned in any appropriateorientation and of any appropriate compactness higher or lower than thecompactness of the remaining part of the central core or body 274 whichremaining part is produced from the web 160 in accordance with theteachings of the present invention and consequently comprises segmentssimilar to the segments of the central core or body 148 described above,i.e. the segments 228, 232 and 236. Thus, the central core or body 274presents two subsegments 278 and 280 corresponding to the subsegments237 and 239, respectively, of the lamella or segment 228 described abovewith reference to FIGS. 8 and 13 and further a narrow segment 279corresponding to the segment 238 of the lamella or segment 228 shown inFIGS. 8 and 13.

In FIG. 15, a highly advantageous characteristic of a mineral fiberplate produced in accordance with the teachings of the present inventionis shown. In the left hand part of FIG. 15, a folded mineral fiber plateis shown designated the reference numeral 284. The plate 284 compriseslamellae or segments one of which constituting the top segment isdesignated the reference numeral 286. The plate 284 defines in itsrelaxed position shown in the left hand part of FIG. 15 an overallheigth of h₁. Provided the plate 284 is exposed to a pressure force orpressure impact, the height of the mineral fiber plate is reduced fromthe height h₁ to the height h₂ indicated in the right hand part of FIG.15 which also discloses the somewhat compressed mineral fiber platedesignated the reference numeral 284' including the top segment or layerwhich in the compacted plate 284' is designated the reference numeral286'.

It is to be emphasized that the pressure or force impact which causes areduction of the height of the mineral fiber plate 284 from h₁ equal to60 cm to h₂ equal to 30 cm is merely of the order of 12-18 kPa. Whereasthe mineral fiber plate 284 may be compressed in the vertical directionas shown in FIG. 15, the plate is extremely strong and basicallyincompressible in directions along the horizontal and transversaldirections defined by the lamellae or segments of the composite platestructure. The mineral plate product 284 is consequently-highlyadvantageous in connection with insulating building structures whichoften require adjustment of one of the dimensions of an insulating platein accordance with the specific dimensions of the building structure inquestion. Instead of reducing the size of a insulating plate to be usedin a building structure, the mineral fiber plate product 284 is easilyadapted to specific dimensional requirements as the product along onedirection which may constitute the length or the width of the plate maybe reduced up till a factor 50% by simple compressing the plate product.The property disclosed in FIG. 15 is further advantageous from apackagning and transportion point of view as the mineral fiber plateproduct 284 may be stored, packaged and transported in a reduced volumeas compared to the unrelaxed volume allowing a reduced packaging andtransportation cost per plate unit.

The composite mineral fiber product produced in accordance with thetechnique described above with reference to FIG. 7 may constitute aninsulating convering to be used in connection with boilers, vessels,pipes, tubings, tubes or the like in which heated water or steam areconducted. The insulating covering shown in FIG. 16 is in its entiretydesignated the reference numeral 290 and comprises a plurality oflamella one of which is designated the reference numeral 294 originatingfrom the lamella or segments of the mineral fiber web 70 described abovewith reference to FIG. 1 and as is evident from FIG. 16 include mineralfibers orientated along transverse directions relative to thelongitudinal direction of the lamella in question and also relative toone another. The insulating covering is provided with an outer foil 292.

Mineral fiber plate products produced in accordance with the teachingsof the present invention and constituting implementations of the mineralfiber plate according to the present invention exhibit improved fireresistance characteristics as compared to similar conventional products.FIGS. 17a and 17b illustrate test conditions of a test which was carriedout by the applicant for comparing a prototype embodiment of the mineralfiber plate according to the present invention and conventional mineralfiber plate products. Mineral fiber plates measuring 600 mm×900 mm andhaving a thickness of 120 mm were produced in accordance with theembodiment shown in FIGS. 13 and 15 and from the conventional fiberplate product in which the mineral fibers are predominantly arrangedalong a direction coinciding with the longitudinal or transversaldirection defined by the major surfaces of the plate product. One sampleof the mineral fiber plate according to the present invention and onesample of the conventional mineral fiber plate product were suspendedhorizontally within a furnace and exposed to elevated temperatures asthe furnace was heated as illustrated in FIG. 17b in which four curvesE, F, G and H are shown. Along the abscissa axis, the period of timesince the initiation of the experiment of test is indicated, and alongthe ordinate axis the temperature is indicated. The curve E representsthe control curve, i.e. the temperature response to which the sampleswere to be exposed within the furnace. The curves F, G and H representthe temperature measured within the furnace and at specific locationsthereof. The samples constituted by the mineral fiber plate according tothe present invention and the conventional mineral fiber plate productwere visually monitored while suspended within the furnace. After 105min, the experiment or test were terminated since the conventionalmineral fiber plate product was deflected approximately 120 mm from theoverall horizontal plane and was about to fall down, whereas the samplesof the mineral fiber plate according to the present invention was merelydeflected approximately 30 mm. During the experiment, the temperature atthe sides of the samples opposite to the sides which were facing thefurnace were monitored. The measuring results are shown in FIG. 17a, inwhich the abscissa represents the same time scale as shown in FIG. 17band in which the ordinate axis represents the temperature at the sidesof the samples opposite to the sides facing the furnace. Four curves, A,B, C and D are shown in FIG. 17a. The curves A and B represent themeasuring results of the sample of the mineral fiber plate according tothe present invention, and the curves C and D represent the measuringresults of the conventional mineral fiber plate product.

The mineral fiber plates according to the present invention and theconventional mineral fiber plate products were analyzed. The mineralfiber plates according to the present invention contained 0.77 kg/mr³bonding agent and oil, and the conventional mineral fiber plate productcontained 0.81 kg/m³ bonding agent and oil.

Conclusion:

The reduced deflection of the mineral fiber plate according to thepresent invention as compared to the conventional mineral fiber plateproducts provides radically improved fire resistance characteristics orproperties since the reduced reflection at extreme, elevatedtemperatures reduces the risk of the plate being deflected to such anextent that the plate firstly produces slots at the junction to adjacentmineral fiber plate and secondly falls down from the suspended state dueto extreme deformation or collapse of the plate structure.

Although the analysis of the chemical composition of the constituents ofthe mineral fiber plate according to the present invention as comparedto the conventional mineral fiber plate product revealed a slightlyincreased content of FeO, 8.3% as compared to 6.3%, the difference incontent of FeO, however, itself is not large enough to explain theimproved integrity of the mineral fiber plates according to the presentinvention as compared to the conventional mineral fiber plate products.

FIGS. 18a and 18b illustrate an advantageous technique of packagingmineral fiber plates according to the present invention in compactedstate. According to the packaging technique illustrated in FIGS. 18a and18b, the characteristic of the mineral fiber plate 284 shown in FIG. 15is employed. In FIG. 18a, a total of four mineral fiber plates 284 arepositioned vertically or standing on a first packaging foil 285 as theplates 284 are positioned having their longitudinal directionsorientated vertically. On top of the plates 284, a second packaging foil287 is positioned. A pressure plate 291 is lowered from a position abovethe second packaging foil 287 and the mineral fiber plates 284 causing acompression of the mineral fiber plates reducing the overall volume ofthe mineral fiber plates to approximately 40-60% of the initial volumeof the mineral fiber plates. After the compression and compacting of themineral fiber plates 284 producing compacted or compressed mineral fiberplates 284 similar to the plate shown in FIG. 15, the first and secondpackaging foils 285 and 287 are joined and sealed together in a heatsealing process or any equivalent sealing proces, e.g. a gluing processor a combined gluing and heat sealing process, so as to produce a sealedpackaging foil 285 enclosing the compacted mineral fiber plates 284within the sealed packaging foil producing a highly compact mineralfiber plates package 289 shown in FIG. 18b and having a volumeconstituting approximately 60-80% of the overall volume of thenon-compacted and non-compressed mineral fiber plates.

The package 289, thus, comprises the compressed or compacted mineralfiber plates designated the reference numeral 284 and first and secondpackage foil segments 285' and 287' which are joined together throughtwo transversal seals 295 and 296 constituting front and rear seals,respectively. The mineral fiber plate according to the present inventionconstitute a product which may be packed within a sealing or enclosuresuch as a foil through the application of a compression ratio during theprocess of compacting the mineral fiber plate of approximately 50%providing a compression ratio of approximately 20% of the finalcompacted or compressed mineral fiber plate. The mineral fiber platemaintains its integrity due to its high compressive strength in itstransversal and elevational directions. The mineral fiber plate furtherexhibits a reduced tendency as compared to conventional mineral fiberplate products to be deformed through the compacting or compressingprocess. Conventional mineral fiber plate products are often deformedthrough an increasing length and width provided the thickness of theproduct is reduced through compacting or compression. Therefore,conventional mineral fiber plate products are to some extent damaged anddeformed through the compacting and compressing process. Furthermore,the damage and deformation of conventional mineral fiber plate productsthrough the application of compacting or compression in the process ofpackaging the mineral fiber plate may reduce the elasticity ofcompression of the plate along the direction of compacting andcompressing the plate. The possibility of packaging mineral fiber platesin a reduced volume occupying merely 60-80% of the initial volume of themineral fiber plates or even less renders it possible to ship moremineral fiber plates in a single shipment as compared to non-compactedand non-compressed mineral fiber plates. The mineral fiber platesaccording to the present invention may recover to approximatly 100% ofthe original volume after the mineral fiber plates have been compactedto 60-80% of the initial volume or even less for an extended period oftime.

The mineral fiber plate according to the present invention furtherexhibits a distinct advantage as compared to most conventional mineralfiber plate products which are stored in a non-compacted andnon-compressed state within a packaging enclosure, such as a packagingfoil of the type shown in FIG. 18b, or contained within a completeencapsulating foil similar to a foil to be described below withreference to FIG. 20, as those edges or corners of the conventionelmineral fiber plate products which are positioned at the outer edges andcorners, respectively, of the package, are permanently deformed andconsequently damaged by the packaging foil which is positionedencircling the mineral fiber plate products confining the mineral fiberplate products within a sealed package. Contrary to the conventionalmineral fiber plate products, the mineral fiber plate according to thepresent invention exhibits a high integrity and mechanical strengthwhich ensures that no part of the mineral fiber plates which areconfined within a package, such as the package 289 shown in FIG. 18b, ispermanently deformed or damaged. Thus, no part of the mineral fiberplates of the package 289 shown in FIG. 18b is permanently deformed ordamaged by the process of sealing the mineral fiber plates within thefoil of the package 289. Even those parts of the mineral fiber platescontained within the package 289 which are positioned at the outer edgesor corners of the package 289 are not, contrary to conventional mineralfiber plate products, permanently deformed or damaged.

It is to be understood that the orientation of the mineral fiber plates284 during the process of packaging the mineral fiber plates isarbitrary since the mineral fiber plates 284 which are positionedvertically in FIG. 18a may be positioned in any arbitrary orientationsuch as a horizontal position and piled on top of one another ratherthan positioned adjacent to one another as shown in FIG. 18a. Providedthe mineral fiber plates 284 are positioned piled on top of one anotherin a substantially horizontal position, the pressure plate 291 or anyequivalent compression or compacting means or tool is reciprocatedhorizontally for compacting the mineral fiber plate 284 along thelongitudinal directions thereof employing the extreme compressibility ofthe mineral fiber plates according to the present invention along thelongitudinal direction of the mineral fiber plates.

In FIG. 19, a presently preferred embodiment of a plant for theproduction of packages containing mineral fiber plates according to thepresent invention is shown. The plant is an on-line production plant inwhich a plurality of cured mineral fiber webs, such as four curedmineral fiber webs 150", 150'", 150^(IV) and 150^(V) or any other numberof cured mineral fiber webs, are processed for producing mineral fiberplates contained within packages containing a total of four mineralfiber plates each or any other number of mineral fiber plates. The curedmineral fiber webs 150", 150'", 150^(IV), 150^(V) are moved forward oncontinuously operated rollers 300', 300", 300'" and 300^(IV). Providedthe cured mineral fiber webs 150", 150'", 150^(IV), and 150^(IV) are tobe stopped, a finned plate element 301 is lifted by means of a motor 302causing the cured mineral fiber webs to be lifted from the rollers 300',300", 300'", and 300^(IV). The cured mineral fiber webs 150", 150'",150^(IV) and 150^(V) are transferred from the rollers 300', 300", 300'"and 300^(IV) to a conveyor belt 304 which is supported on a drive roller306 which is powered by a motor 308 and an idler roller 310. The curedmineral fiber webs 150", 150'", 150^(IV) and 150^(V) are as isillustrated in FIG. 19 positioned on the edges allowing that the curedmineral fiber webs may be compressed vertically as will be furtherdiscussed below. The cured mineral fiber webs 150", 150'", 150^(IV) and150^(V) are received and supported between opposite conveyor belts 312and 314 which are operated in syncronism with the conveyor belt 304 andserve the purpose of supporting the cured mineral fiber webs as themineral fiber webs are introduced into a cutting machine 316.

The cutting machine 316 basically comprises a yoke-like supportstructure 318 which supports upper and lower runners 320 and 322 onwhich rotating wheels 324 and 326, respectively, are supported. Therotating wheels 324 and 326 are powered by a motor, not shown on thedrawings, and supports a closed loop cutting string 328 whichconstitutes the cutting tool or cutting element of the cutting machine316. As the cured mineral fiber webs 150", 150'", 150^(IV) and 150^(V)are moved passed the cutting machine 316 through the yoke-like frame 318of the cutting machine to a predetermined distance beyond the cuttingmachine, the runners 320 and 322 are activated causing the runners tomove towards the cured mineral fiber webs 150", 150'", 150^(IV) and150^(V) causing the cutting string 328 to be forced through the curedmineral fiber webs and separating four mineral fiber plate segments fromthe cured mineral fiber webs 150", 150'", 150^(IV) and 150^(V). Thecured mineral fiber plate segments separated from the cured mineralfiber webs are received on a conveyor belt 330 which is supported by tworollers 332 and 334 and are further supported by opposite, verticalconveyor belts 336 and 338 basically serving the same purpose as theabove described conveyor belts 312 and 314, respectively, with thepurpose of supporting the cured mineral fiber plate segments as thecured mineral fiber plate segments are propelled by the conveyor belt330.

The mineral fiber plate segments are further advanced on a plurality ofrollers one of which is designated the reference numeral 340 and arecompressed by means of opposite, vertical conveyor belts 342, 344 and346, 348. Provided the mineral plate segments are to be stopped, afinned plate segment 349 similar to the above described finned platesegment 301 is activated by means of a motor 350.

From the rollers comprising the roller 340, the mineral fiber platesegments which have been positioned and compressed for registering theindividual mineral fiber plate segments properly are introduced into apackaging section 360 of the plant shown in FIG. 19. The packagingsection 360 is shown in the lower part of FIG. 19 and comprises ahorizontal lower conveyor belt 362 which is supported on rollers 364 and366 and further includes a plurality of supporting rollers one of whichis designated the reference numeral 368. Opposite the horizontalconveyor belt 362, a pressure applying conveying belt 370 is positionedwhich includes a first sloping section 372 and a second horizontalsection 374. The conveyor belt 370 includes a plurality of rollers 376,378, 380 and 382 serving the purpose of guiding the conveyor belt forproducing the sloping section 372 and the horizontal section 374. Theconveyor belt 370 further includes a plurality of support or pressurerollers 386 similar to the rollers 368 of the conveyor belt 362.

On the conveyor belt 362, a total of four sets 384', 384'" and 384^(IV)are supported, each including four mineral fiber plate segmentsoriginating from the cured mineral fiber webs 150", 150'", 150^(IV) and150^(V). Between the lower sides of the sets 384', 384", 384'" and384^(IV) and the upper side of the conveyor belt 362, a lower packagingfoil 388 is confined which foil is supplied from a packaging foil supplyroll 390. Similarly, an upper packaging foil 392 is confined between theupper sides of the sets 384', 384", 384'" and 384^(IV) and the lowerside of the sloping section 372 of the upper conveyor belt 370 whichupper packaging foil is supplied from a packaging foil supply roll 394.As the sets 384', 384", 384'" and 384^(IV) are advanced from left toright by means of the lower conveyor belt 362 and also the upperconveyor belt 370, which are moved in synchromism, the sloping section372 of the upper conveyor belt 370 causes the sets to be compressed in acompressing process similar to the process described above withreference to FIGS. 15 and also FIG. 18a. During the process ofcompressing the sets 384', 384", 384'" and 384^(IV), the packaging foils388 and 392 are also advanced along with the individual sets and areintroduced into a finalizing section of the packaging section comprisingthe horizontal section 374 of the upper conveyor belt 370 in whichfinalizing section the packaging foils 388 and 390 are joined togetheras will be readily described below. For initiating the process ofjoining the foils 388 and 392 together, opposite, vertical guidingplates 395 and 396 are provided which serve the purpose of folding theouter edges of the foil 388 upwardly allowing the outer longitudinaledges of the foils 388 and 392 to be joined together. For positioningthe outer longitudinal edges of the foils 388 and 392 properly, a firstset of rollers 398', 398" and 398'" is provided which serves the purposeof catching the outer longitudinal edge of the foil 388 and maintainingthe outer longitudinal edge of the foil 388 in a stretched, downwardlybent position relative to the guide 396. Similarly, a second set ofrollers 400', 400" and 400'" are provided, each comprising twoindividual rollers serving the purpose of catching the outerlongitudinal edge of the upper packaging foil 392 for stretching theupper packaging foil 392 and for positioning the outer longitudinal edgeof the upper foil 392 in proper overlying relationship relative to thedownwardly bent outer longitudinal edge of the lower packaging foil 388.After the outer longitudinal edges of the upper and lower packagingfoils 392 and 388, respectively, are properly positioned in overlappingrelationship, the upper and lower packaging foils 392 and 388 areexposed to an air stream generated by a blower outlet 402 which servesthe purpose of blowing away any excessive material from the outer sidesurfaces of the packaging foils and of stretching the packaging foilsbefore the packaging foils are introduced into a sealing assembly 404 inwhich the upper and lower packaging foils 392 and 388 are heat sealedtogether by exposure to heat. After the heat sealing process, the heatsealed outer longitudinal edges of the packaging foils 392 and 388 arecooled by the supply of cooling air provided from a cooling air outlet406. It is to be understood that elements similar to the first andsecond sets of rollers 398' etc. and 400' etc, respectively, the airoutlet 402, the heat sealing assembly 404 and the cooling air outlet 406are provided at the opposite side of the packaging machine at the guide395.

From the upper and lower conveyor belts 362 and 370, the sets 384',384", 384'" and 384^(IV) are transferred to a heat sealing section 410which comprises two opposite vertically reciprocating sealing clawscomprising an upper clamp and a lower clamp 414 by means of which theupper and lower packaging foil 392 and 388, respectively, are joinedtogether along the transversal, horizontal front and rear edges of thesets 384' etc. As the heat sealing clamps 412 and 414 are moved towardsone another, causing the upper and lower packaging foils 392 and 388 tobe jammed between the heat sealing clamps, a rearmost horizontal seal ofa set of compressed and compacted mineral fiber plate segments isproduced which set is already sealed along the front edge and the sideedges thereof. Thus, a hermetically sealed set contained within a sealedpackage is produced. At the same time, a front horizontal seal isproduced at the succeeding set. The clamps 412 and 414 preferably alsoincludes a cutter serving the purpose of separating the preceedingfinished package from the continuous upper and lower packaging foils 392and 388, respectively, which package is received between opposite lowerand upper conveyor belts 416 and 418. The lower conveyor belt 416constitutes a horizontal conveyor belt, whereas the upper conveyor belt418 includes a horizontal first section and a diverging and upwardlysloping second section. The first section serves the purpose ofmaintaining the finished package including a total of four mineral fiberplate segments in the compressed and compacted state whereas thediverging and upwardly sloping second sections serves the purpose ofallowing the compacted and compressed mineral fiber plate segments toexpand to a small degree for producing a complete stretching of thematerial of the package wihtin which the mineral fiber plate segmentsare contained.

In FIG. 20, a package 389 produced in the packaging plant describedabove with reference to FIG. 19 is shown. The package 389 provides acomplete and hermetic encasing of the mineral fiber plate segmentscontained within the sealing packaging foils. Like the above describedpackage 289, the mineral fiber plate segments are compacted to 60-80% ofthe initial volume, or even less, such as 40-50% of the initial volume,providing a package which occupies far less space as compared tononcompacted mineral fiber plate segments. The mineral fiber platesegments produced in accordance with the teachings of the presentinvention may recover to approximately 100% of the original or initialvolume after the mineral fiber plate segments have been compacted to theabove percentage for an extended period of time. In FIG. 20, the flapsproduced from the upper and lower packaging foils 392 and 388,respectively, described above with reference to FIG. 19, are alsoillustrated. Thus, the reference numeral 420 refers to the upperpackaging foil part produced as the outer longitudinal packaging foilsegments are sealed together by means of the sealing assembly 404 asdescribed above with reference to FIG. 19. The reference numerals 422and 424 designate the flaps produced at the front edge of the package asthe clamps 412 and 414 are moved towards one another for producing therearmost sealing of the preceding package corresponding to the flaps422' and 424' shown in FIG. 20 and for separating the preceding packagefrom the upper and lower packaging foils 492 and 488, respectively. Thereference numeral 426 designates the front seal established by means ofthe heated clamps 412 and 414. Similar seals are, as will be evidentfrom the above description, established circumferentially encircling themineral fiber plate segments contained within the package 389.

In FIGS. 21, 22, 23, and 24, a particular aspect of the presentinvention is illustrated, viz. an aspect relating to a particulartechnique of producing tubular insulating elements. In FIG. 21, anassembly 430 is shown which is composed of three mineral fiber platesegments 150", 150'", and 150^(IV) produced in accordance with theteachings of the present invention as described above with reference toFIGS. 1-5. The mineral fiber plate segments 150", 150'", and 150^(IV)are glued together, producing an integral assembly. By means of acutting string or a saw blade 432, tubular insulating elements are cutfrom the assembly 430, producing tubular insulating elements ofdifferent configurations. The reference numeral 434 designates a largediameter tubular insulating element which is produced from all threemineral fiber plate segments 150", 150'", and 150^(IV). The referencenumeral 436 designates a single smaller diameter tubular insulatingelement which is produced from a single mineral fiber plate segment,viz. the mineral fiber plate segment 150^(IV). Three additional,identical tubular insulating elements are also shown in FIG. 21.

The reference numeral 438 designates a tubular insulating element of aconfiguration somewhat different from the configuration of the largerdiameter tubular insulating element 434 and the smaller diameter tubularinsulating element 436. Whereas the tubular insulating elements 434 and436 constitute tubular insulating elements having circular cylindricalouter and inner walls of concentric configuration, the tubularinsulating element 438 constitutes an insulating element having acircular cylindric outer wall and an inner wall providing a flexibleinner side which is adaptable to varying applications. The tubularinsulating elements 434, 436, and 438 exhibit a highly advantageouscapability, as the tubular insulating elements are flexible, allowingthe tubular insulating elements to be bent for adapting the tubularinsulating element to a specific configuration. In FIG. 22, the tubularinsulating element 434 is shown in a bent configuration, allowing thetubular insulating element to be used in connection with a curved pipeor the like. The outer surface of the tubular insulating element 434 iscovered by a coating 440 which may constitute a thin plastic foil or areinforcing aluminum foil. Examples of foils are plastics foils, e.g.woven or non-woven polypropylene foils, such as spun-bound foils,aluminum-reinforced plastics foils or paper, crepe paper or combinationsthereof. Fiber-reinforced materials may also be applied, e.g. glassfiber-reinforced plastic material or combinations thereof. The coating440 may be adhered to the outer surface of the tubular insulatingelement 434 in numerous ways through a complete surface adhesion oradhesion in individual spots or along specific lines of adhesionextending circumferentially relative to the tubular insulating element,parallel to the longitudinal axis of the tubular insulating element orin a different orientation relative to the circumferential andlongitudinal directions of the circular cylindrical insulating element434. It is to be realized that the elastic capability of the mineralfiber plate segments 150", 150'", and 150iv shown in FIG. 21 may beutilized in different ways by producing the tubular insulating elementsin a different orientation relative to the orientation of the mineralfiber plate segment 150'", etc., providing an insulating element such asa tubular insulating element exhibiting a characteristic capability ofallowing the insulating element to be compacted in a specific directiondetermined by the direction determined by the mineral fiber platesegments 150", etc. along which direction the mineral fiber platesegments are compactable.

In FIG. 23, the above characteristic property is illustrated as a totalof four mineral fiber plate segments 444', 444", 444'", and 444^(IV) arepositioned in mutually parallel relationship defining an assembly 442.By means of the above described cutting wire or saw blade 432, tubularinsulating elements 434' and 438' of configurations similar to the abovedescribed tubular insulating elements 434 and 438, respectively, areproduced. Contrary to the tubular insulating elements described abovewith reference to FIG. 21, the tubular insulating elements 434' and 438'shown in FIG. 23 extend perpendicularly to the outer surfaces of theindividual mineral fiber plate segments 444', etc. Dependent on thecharacteristic properties of the mineral fiber plate segments 444',444", and 444"", and 444^(IV), the tubular insulating elements 434' and438' produced therefrom exhibit characteristics as to compactness orflexibility. In FIG. 24, the tubular insulating element 434' is shownprovided with an outer coating 440'. The coating 440' may be producedfrom any of the materials discussed above with reference to FIG. 22.

Table 1 below illustrates measuring results relating to thermalinsulating properties and compression properties of mineral fiber platesaccording to the present invention and produced with varying heightcompression ratio, and a conventional board or plate. The density of allboards or plates were 80 kg/mr³. The signature λ refers to thecoefficient of heat transmission as expressed in mW/mK, the signature δrefers to the compressive strength as expressed in kPa, and thesignature E refers to the elasticity of compression as expressed in kPa.The indices e, t and l indicates the direction of measurement of theproperty in question relating to the above defined directions e:elevational direction, t: transversal direction and l: longitudinaldirection.

                  TABLE 1                                                         ______________________________________                                        Plates according to the present invention                                     Height compression ratio                                                                              Conventional                                          1:1       1.2:1   1.37:1    2.3:1 board or plate                              ______________________________________                                            36.3      35.5    35.0    33.0  32.5                                      δ.sub.e                                                                     24        20      17      11    8                                         E.sub.e                                                                           350       350     280     110   110                                       HD t                                                                              39.5      39.0    40.0    39.3  38.0                                      δ.sub.t                                                                     .46       46      46      46    60                                        E.sub.t                                                                           2400      2400    1750    1250  3400                                      HD l                                                                              33.0      34.5    35.0    36.0                                            δ.sub.l                                                                     8.5       15.5    15.5    19.0                                            E.sub.l                                                                           120       220     250     330                                             ______________________________________                                    

From Table 1, the following conclusions may be made:

The values of λ_(e) of the plates according to the present invention areof the order of 35-36 mW/mK and consequently better than the value ofλ_(t) of conventional boards or plates being of the order of 38 mW/mK,however, somewhat larger than the λ_(e) of the conventional boards orplates being of the order of 32.5 mW/mK.

The application of height compression during the process of producingthe mineral fiber plates according to the present invention renders itpossible to improve the value of λ_(e) by reducing the value from 35-36mW/mK as indicated in Table 1 above to approximately 33 mW/mK.

The compressive strength δ_(e) of the plates according to the presentinvention is of the order of 17-24 kPa and consequently far better thanthe value of δ_(e) of the conventional board or plate being of the orderof 8 kPa. As is evident from Table 1, the value of δ_(e) of the platesaccording to the present invention is dependent on the application ofheight compression and in particular the height compression ratio. Thevalue of E_(e) of the plates according to the present invention is ofthe order of 280-350 kPa provided a fairly low height compression ratiois applied. Consequently, the elasticity of compression of the mineralfiber plates according to the present invention is consequentlysubstantially better than the elasticity of compression of theconventional board or plate along the elevational direction of theboards or plates, i.e. perpendicular to the longitudinal and transversaldirections of the boards or plates.

The product produced as described above with reference to FIG. 7constitutes a so-called wired insulating mat for insulating e.g.boilers, vessels, pipes, tubings, tubes or the like. It is comtemplatedthat the application of height compression during the process ofproducing the product reduces the difference in thermal insulatingproperty between any two products. It is, however, to be realized thatthe application of height compression above a certain limit may overallimprove the thermal insulating property of the final product as theimproved compression properties may reduce the number of supports of anexternal facing so that the number of thermal bridges are completely orto a certain extent eliminated.

Experiments have revealed that the so-called wired mat is far more easyto handle and mount as compared to similar conventional products.

Below, four tables illustrates measuring results of comparable productsand products according to the present invention. Table 2 illustratesresults of a mineral fiber plate according to the present invention andof the type shown in FIG. 10 (identified by T) as compared toconventional boards or plates constituted by a board produced by thecompany Scan Glasuld A/S (identified by U), and boards produced by theapplicant's Danish division and German division (identified by V and W,respectively). All boards or plates had a thickness of 30 mm.

                  TABLE 2                                                         ______________________________________                                             Density Deformation                                                                             Bending  Contraction                                   Name kg/m.sup.3                                                                            at 3 kN/M.sup.2                                                                         Resistance (g)                                                                         (mm)    (mW/mK)                               ______________________________________                                        T    42      2,7       1100     3,3     41                                    U    25      4,6       1200     1,9     43                                    V    37      2,8       1400     2,9     43                                    W    42      5,0       1000     5,5     41                                    ______________________________________                                    

Table 3 similarly illustrates the properties of Table 2 converted into ascore ranging from 1 to 10.

                  TABLE 3                                                         ______________________________________                                                      Deformation                                                                             Bending                                               Name Density  at 3 kN/M.sup.2                                                                         Resistance                                                                             Contraction                                                                           HZ,1/32                              T    8        10        8        10      9                                    U    10       5         9        9       7                                    V    9        8         8        7       7                                    W    8        5         10       4       9                                    ______________________________________                                    

Table 4 illustrates the properties of the flexible mineral fiber plateshown in FIG. 15 according to the present invention (identified by X) ascompared to conventional so-called FLEXI A-BATTS™ plates or boardsmanufactured by the applicant (identified by Y) and products produced bythe competitor, the Danish company Scan Glasuld A/S (identified by Z).The table clearly illustrates the advantageous combination of highthermal insulating capability, high flexibility and high compressionstiffness.

                  TABLE 4                                                         ______________________________________                                                           Flexi-          Compression                                          value    bility    Density                                                                             stiffness                                  PRODUCT   mW/mK    (0-10)    (kg/m.sup.3)                                                                        (0-10)                                     ______________________________________                                        X         37       8         32    10                                         Y         36       4         32    4                                          Z         36       3         17    2                                          ______________________________________                                    

Table 5 illustrates the properties of the above described wired matproduced as above with reference to FIG. 7 (identified by XX) and asimilar conventional wired product manufactured by the applicant(identified by YY). Score ranging from 1 to 10.

                  TABLE 5                                                         ______________________________________                                                                        Thickness                                                Installation                                                                             tolerances                                              PRODUCT   (0-10)      (0-10)    (0-10)                                        ______________________________________                                        XX        7           7         10                                            YY        10          3         4                                             ______________________________________                                    

Experiments have revealed that the flexible property of the mineralfiber plates according to the present invention as illustrated in FIG.15 renders it possible to provide more reliable and perfect insulationas compared to the application of comparable conventional products whichare flexible.

Tests were made for comparing a so-called FLEXI A-BATTS™ manufactured bythe applicant and a mineral fiber plate product as shown in FIG. 15.Both products were mounted in an aperture of a width of 880 mm. Bothproducts had a width exceeding the width of the aperture by 40 mm.

Results:

Conventional boards or plates of the type FLEXI A-BATTS™ of a thicknessof 100 mm and a density of 32 kg/m³ were mounted without the applicationof physical impact. During the compression of the flexible part of theboards or plates, the boards or plates were folded at the center of theboards or plates. After the mounting, only minor insulating faults wereobserved. Overall homogeneous surfaces were produced.

Mineral fiber plates according to the present invention of a thicknessof 100 mm and a density of 39 kg/m³ were easily mounted producing aperfect filling out. The plates were folded during the process ofproducing the plates to a width of 120 mm and were compressed within thecuring furnace to an overall width of 100 mm.

Due to the folded structure of the mineral fiber plate according to thepresent invention, the plate is very easily compressible still providinga density of the order of approximately 40 kg/mr³. It is contemplatedthat the application of height compression during the process ofproducing the mineral fiber plate according to the present invention mayimprove the integrity of the final product. However, it has been provedthat height compression may to some extent reduce the flexibility of theproduct.

As compared to conventional boards or plates, the mineral fiber plateaccording to the present invention provides an increased compressivestrength and increased elasticity of compression of the order of 2-2.5times. Consequently, the mineral fiber plate according to the presentinvention may be exposed to larger pressure impact as compared to theconventional boards or plates without producing insulation faults. Asverified above the improved flexibility is believed to provide a moreadequate integration or junction to the existing structure which is tobe insulated.

On the basis of the measurements discussed above, it has been provedthat the mineral fiber plate according to the present invention mayprovide a flexibility of the order of 60 mm at a load of 2 kPa in thelongitudinal direction. Provided the flexibility is transformed intomodulus of elasticity, a modulus of elasticity of no more than 20 kPa isprovided at a width of 600 mm of the plate and similarly a modulus ofelasticity of no more than 30 kPa at a length of 900 mm. A conventionalmineral fiber board or plate of a density of 35 kg/m³ exhibits a modulusof elasticity of the order of 130-225 kPa, however, to some extentdepending on the predominant orientation of the mineral fibers of theboard or plate. It is to be realized that the optimum flexible mineralfiber plate exhibits a modulus of elasticity varying between 20 and 30kPa, provided the length of the plate is between 600 and 900 mm,respectively. The mineral fiber plate according to the present inventionand of the type disclosed in FIG. 13 exhibits a modulus of elasticity ofapproximately 20 kPa, provided the mineral fiber plate has been exposedto height compression such as a ration of 1:1 during the process ofproducing the mineral fiber plate and similarly a modulus of elasticityof approximately 30 kPa provided the mineral fiber plate has beenexposed to height compression during the process of producing themineral fiber plate of such as a ratio of 1.33:1. In the transversaldirection, the mineral fiber plate according to the present inventionexhibits a modules of elasticity which is comparable with the modulus ofelasticity of the conventional mineral fiber board or plate such as amodulus of elasticity of approximately 200 kPa.

We claim:
 1. A method of producing a cured non-woven mineral fiber webcomprising the following steps:a) producing a first non-woven mineralfiber web defining a first longitudinal direction parallel with saidfirst mineral fiber web and a first transversal direction parallel withsaid first mineral fiber web, said first mineral fiber web containingmineral fibers arranged in said first longitudinal direction thereof andincluding a first curable bonding agent, b) moving said first mineralfiber web in said first longitudinal direction, c) arranging segments ofsaid first mineral fiber web in partly mutually overlapping relationshipand transversely relative to said first longitudinal direction and saidfirst transversal direction so as to produce a second non-woven mineralfiber web, said second mineral fiber web defining a second longitudinaldirection and a second transversal direction and containing mineralfibers arranged transversely relative to said second longitudinaldirection and said second transversal direction and generallytransversely relative to one another, d) moving said second mineralfiber web in said second longitudinal direction, e) folding said secondmineral fiber web transversely relative to said second longitudinaldirection and parallel with said second transversal direction so as toproduce undulations extending perpendicular to said second longitudinaldirection and parallel with said second transversal direction and toproduce a third non-woven mineral fiber web, said third mineral fiberweb containing mineral fibers arranged transversely relative to oneanother and transversely relative to said second longitudinal directionand said second transversal direction, f) moving said third non-wovenmineral fiber web in said second longitudinal direction, and g) curingsaid first curable bonding agent so as to cause said mineral fibers ofsaid third mineral fiber web to bond to one another, thereby formingsaid cured non-woven mineral fiber web.
 2. The method according to claim1, said arranging of said segments of said first mineral fiber web inpartly mutually overlapping relationship of step c) comprising theinitial step of cutting said first mineral fiber web into said segments.3. The method according to claim 1, said arranging of said segments ofsaid first mineral fiber web in partly mutually overlapping relationshipof step c) comprising folding said segments of said first mineral fiberweb transversely relative to said first longitudinal direction and saidfirst transversal direction.
 4. The method according to claim 1, saidarranging of said segments of said first mineral fiber web in partlymutually overlapping relationship of step c) being performed so as toposition said segments of said first mineral fiber web along a directiondefining an angle larger than 0° and smaller than 90° relative to saidsecond transversal direction.
 5. The method according to claim 1, saidfolding of said second mineral fiber web of step e) being performed as atransverse folding relative to said second longitudinal direction. 6.The method according to claim 1, said first mineral fiber web being amineral fiber web of having an area weight between 0.1 kg/m² and 1.0kg/m².
 7. The method according to claim 1, said second mineral fiber webbeing a mineral fiber web of an area weight between 0.3 kg/m² and 3.0kg/m².
 8. The method according to claim 1, further comprising theadditional step of height compressing said second mineral fiber webproduced in step c).
 9. The method according to claim 1, furthercomprising the additional step of longitudinally compressing said secondmineral fiber web produced in step c).
 10. The method according to claim1, further comprising the additional step of transversally compressingsaid second mineral fiber web produced in step c).
 11. The methodaccording to claim 1, further comprising the additional step of heightcompressing said third mineral fiber web produced in step e).
 12. Themethod according to claim 1, further comprising the additional step oflongitudinally compressing said third mineral fiber web produced in stepe).
 13. The method according to claim 1, further comprising theadditional step of transversally compressing said third mineral fiberweb produced in step e).
 14. The method according to claim 1, furthercomprising the following steps substituting step g):h) producing afourth non-woven mineral fiber web defining a third longitudinaldirection parallel with said fourth mineral fiber web, said fourthmineral fiber web containing mineral fibers and including a secondcurable bonding agent, said fourth mineral fiber web being a mineralfiber web of a higher compactness as compared to said third mineralfiber web, i) adjoining said fourth mineral fiber web to said thirdmineral fiber web in facial contact therewith for producing a fifthcomposite mineral fiber web, and j) curing said first and second curablebonding agents so as to cause said mineral fibers of said fifthcomposite mineral fiber web to bond to one another, thereby forming saidcured non-woven mineral fiber web.
 15. The method according to claim 14,said fourth mineral fiber web being produced by separating a separatelayer of said first mineral fiber web therefrom and by compacting saidseparate layer for producing said fourth mineral fiber web.
 16. Themethod according to claim 14, said fourth mineral fiber web beingproduced by separating a separate layer of said second mineral fiber webtherefrom and by compacting said separate layer for producing saidfourth mineral fiber web.
 17. The method according to claim 14, saidfourth mineral fiber web being produced by separating a separate layerof said third mineral fiber web therefrom and by compacting saidseparate layer for producing said fourth mineral fiber web.
 18. Themethod according to claim 15, said compacting of said separate layercomprising the step of folding said separate layer so as to produce saidfourth mineral fiber web containing mineral fibers arranged transverselyrelative to said third longitudinal direction of said fourth mineralfiber web.
 19. The method according to claim 14, comprising theadditional step similar to the step h) of producing a sixth non-wovenmineral fiber web similar to said fourth mineral fiber web, and the stepof adjoining in step i) said sixth mineral fiber web to said thirdmineral fiber web in facial contact therewith so as to sandwich saidthird mineral fiber web between said fourth and sixth mineral fiber websin said fifth composite mineral fiber web.
 20. The method according toclaim 14, said third longitudinal direction being perpendicular to saidsecond longitudinal direction.
 21. The method according to claim 14,said third longitudinal direction being identical to said secondlongitudinal direction.
 22. The method according to claim 14, comprisingthe additional step of compressing said fifth composite mineral fiberweb prior to curing said fifth composite mineral fiber web in step j).23. The method according to claim 1, further comprising the followingsteps prior to step e):k) producing a seventh non-woven mineral fiberweb defining a fourth longitudinal direction parallel with said seventhmineral fiber web, said seventh mineral fiber web containing mineralfibers and including a third curable bonding agent, said seventh mineralfiber web being a mineral fiber web of a higher compactness as comparedto said second mineral fiber web, and l) adjoining said seventh mineralfiber web to said second mineral fiber web produced in step c) in facialcontact therewith, prior to step e), for producing an eighth compositemineral fiber web to be folded in step e) for producing said thirdnon-woven mineral fiber web, and step g) also including curing saidthird curable bonding agent.
 24. The method according to claim 23, saidseventh mineral fiber web being produced by separating a separate layerof said first mineral fiber web therefrom and by compacting saidseparate layer for producing said seventh mineral fiber web.
 25. Themethod according to claim 23, said seventh mineral fiber web beingproduced by separating a separate layer of said second mineral fiber webtherefrom and by compacting said separate layer for producing saidseventh mineral fiber web.
 26. The method according to claim 24, saidcompacting of said separate layer comprising the step of folding saidseparate layer so as to produce said seventh mineral fiber webcontaining mineral fibers arranged transversely relative to said fourthlongitudinal direction of said seventh mineral fiber web.
 27. The methodaccording to claim 1, further comprising the step of applying a coveringto a side surface or both side surfaces of said third mineral fiber web.28. The method according to claim 1, further comprising the step ofapplying a covering to a side surface or both side surfaces of saidfifth composite mineral fiber web.
 29. The method according to claim 1,said curing being performed by means of a curing oven.
 30. The methodaccording to claim 1, further comprising the step of cutting said curednon-woven mineral fiber web into plate segments.
 31. A method accordingto claim 1, further comprising:providing a package, arranging said curednon-woven mineral fiber web within said package, compacting said curednon-woven mineral fiber web for substantially reducing the overallvolume of said mineral fiber web to 30-95% of the overall volume of saidnon-compacted mineral fiber web, and sealing said package for providinga sealed package within which said mineral fiber web is kept in acompacted state in which the overall volume of said mineral fiber plateconstitutes 30-100% of the overall volume of said non-compacted mineralfiber plate.
 32. The method according claim 31, further comprisingpackaging a plurality of mineral fiber webs, each defining a respectivefirst direction, and said said mineral fiber webs within said packageincluding arranging said plurality of mineral fiber webs within saidpackage so as to arrange said mineral fiber webs of said plurality in amutually parallel relationship and having said respective firstdirections of said mineral fiber webs positioned parallel to oneanother.
 33. The method according to claim 31, said package beingconstituted by a sealable thermoplastic foil to be wrapped around andsealed around said compacted mineral fiber web after said compacting ofsaid mineral fiber web.
 34. The method according to claim 4, where inthe arranging step is performed so as to position said segments of saidfirst mineral fiber web along a direction defining an angle larger thanabout 10° and smaller than about 60° relative to said second transversaldirection.
 35. The method according to claim 4, where in the arrangingstep is performed so as to position said segments of said first mineralfiber web along a direction defining an angle larger than about 20° andsmaller than about 50° relative to said second transversal direction.36. The method according to claim 6, wherein the area weight of thefirst mineral fiber web is between 0.2 kg/m² and 0.6 kg/m².
 37. Themethod according to claim 7, wherein the second mineral fiber webcomprises an area weight between 0.5 kg/m² and 2.0 kg/m².
 38. The methodaccording to claim 31, wherein compacting reduces the overall volume ofthe mineral fiber plate to 30-85% of the overall volume of thenon-compacted mineral fiber plate.
 39. The method according to claim 31,wherein compacting reduces the overall volume of the mineral fiber plateto 40-60% of the overall volume of the non-compacted mineral fiberplate.
 40. The method according to claim 31, wherein the mineral fiberplate is kept in a compacted state in which the overall volume of themineral fiber plate constitutes 50-90% of the overall volume of thenon-compacted mineral fiber plate.
 41. The method according to claim 31,wherein the mineral fiber plate is kept in a compacted state in whichthe overall volume of the mineral fiber plate constitutes 60-80% of theoverall volume of the non-compacted mineral fiber plate.
 42. The methodaccording to claim 33, wherein the sealable thermoplastic foil is a heatsealable thermoplastic foil.
 43. A plant for producing a cured non-wovenmineral fiber web comprising:a) first means for producing a firstnon-woven mineral fiber web defining a first longitudinal directionparallel with said first mineral fiber web and a first transversaldirection parallel with said first mineral fiber web, said first mineralfiber web containing mineral fibers predominantly arranged generally insaid first longitudinal direction thereof and including a first curablebonding agent, b) second means for moving said first mineral fiber webin said first longitudinal direction, c) third means for arrangingsegments of said first mineral fiber web in partly mutually overlappingrelationship transversely relative to said first longitudinal directionand said first transversal direction so as to produce a second non-wovenmineral fiber web, said second mineral fiber web defining a secondlongitudinal direction and a second transversal direction and containingmineral fibers predominantly arranged generally transversely relative tosaid second longitudinal direction and said second transversal directionand generally transversely relative to one another, d) fourth means formoving said second mineral fiber web in said second longitudinaldirection, e) fifth means for folding said second mineral fiber webtransversely relative to said second longitudinal direction and parallelwith said second transversal direction to produce undulations extendingperpendicular to said second longitudinal direction and parallel withsaid second transversal direction, and to produce a third non-wovenmineral fiber web, said third mineral fiber web containing mineralfibers predominantly arranged generally transversely relative to oneanother and generally transversely relative to said second longitudinaldirection and said second transversal direction, f) sixth means formoving said third non-woven mineral fiber web in said secondlongitudinal direction, and g) seventh means for curing said firstcurable bonding agent so as to cause said mineral fibers of said thirdmineral fiber web to bond to one another, thereby forming said curednon-woven mineral fiber web.
 44. The plant according to claim 43, saidthird means for arranging said segments of said first mineral fiber webin partly mutually overlapping relationship being adapted to perform theinitial step of cutting said first mineral fiber web into said segments.45. The plant according to claim 43, said third means for arranging saidsegments of said first mineral fiber web in partly mutually overlappingrelationship being adapted to fold said segments of said first mineralfiber web transversely relative to said first longitudinal direction andsaid first transversal direction.
 46. The plant according to claim 43,said third means for arranging said segments of said first mineral fiberweb in partly mutually overlapping relationship being adapted to performsaid arranging so as to position said segments of said first mineralfiber web in partly mutually overlapping relationship along a directiondefining an angle larger than 0° and smaller than 90° relative to saidfirst longitudinal direction.
 47. The plant according to claim 43, saidfifth means for folding said second mineral fiber web being adapted toperform said folding as a transverse folding relative to said secondlongitudinal direction.
 48. The plant according to claim 43, said firstmineral fiber web being a mineral fiber web having an area weightbetween 0.1 kg/m² and 1.0 kg/m².
 49. The plant according to claim 43,said second mineral fiber web being a mineral fiber web having an areaweight between 0.3 kg/m² and 3.0 kg/m².
 50. The plant according to claim43, further comprising eighth means for height compressing said secondmineral fiber web produced by said third means.
 51. The plant accordingto claim 43, further comprising ninth means for longitudinallycompressing said second mineral fiber web produced by said third means.52. The plant according to claim 43, further comprising tenth means fortransversally compressing said second mineral fiber web produced by saidthird mean.
 53. The plant according to claim 43, further comprisingeleventh means for height compressing said third mineral fiber webproduced by said fifth means.
 54. The plant according to claim 43,further comprising twelfth means for longitudinally compressing saidthird mineral fiber web produced by said fifth means.
 55. The plantaccording to claim 43, further comprising thirteenth means fortransversally compressing said third mineral fiber web produced by saidfifth means.
 56. The plant according to claim 43, further comprising theadditional means for substituting said seventh means and comprising:g)fourteenth means for producing a fourth non-woven mineral fiber webdefining a third longitudinal direction parallel with said fourthmineral fiber web, said fourth mineral fiber web containing mineralfibers and including a second curable bonding agent, said fourth mineralfiber web being a mineral fiber web of a higher compactness as comparedto said third mineral fiber web, i) fifteenth means for adjoining saidfourth mineral fiber web to said third mineral fiber web in facialcontact therewith for producing a fifth composite mineral fiber web, andj) said seventh means being adapted to cure said first and secondcurable bonding agents so as to cause said mineral fibers of said fifthcomposite mineral fiber web to bond to one another, thereby forming saidcured non-woven mineral fiber web.
 57. The plant according to claim 56,said fourth mineral fiber web being produced by means of sixteenth meansfor separating a separate layer of said first mineral fiber webtherefrom and by compacting said separate layer for producing saidfourth mineral fiber web.
 58. The plant according to claim 56, saidfourth mineral fiber web being produced by means of seventeenth meansfor separating a separate layer of said second mineral fiber webtherefrom and by compacting said separate layer for producing saidfourth mineral fiber web.
 59. The plant according to claim 56, saidfourth mineral fiber web being produced by means of eighteenth means forseparating a separate layer of said third mineral fiber web therefromand by compacting said separate layer for producing said fourth mineralfiber web.
 60. The plant according to claim 57, said compacting of saidseparate layer being performed by means of nineteenth means for foldingsaid separate layer so as to produce said fourth mineral fiber webcontaining mineral fibers arranged transversely relative to said thirdlongitudinal direction of said fourth mineral fiber web.
 61. The plantaccording to claim 56, further comprising twentieth means similar tosaid fourteenth means for producing a sixth non-woven mineral fiber websimilar to said fourth mineral fiber web, and twenty-first means similarto said fifteenth means for adjoining said sixth mineral fiber web tosaid third mineral fiber web in facial contact therewith so as tosandwich said third mineral fiber web between said fourth and sixthmineral fiber webs in said fifth composite mineral fiber web.
 62. Theplant according to claim 56, said third longitudinal direction beingperpendicular to said second longitudinal direction.
 63. The plantaccording to claim 56, said third longitudinal direction being identicalto said second longitudinal direction.
 64. The plant according to claim56, further comprising twenty-second means for compressing said fifthcomposite mineral fiber web prior to curing said fifth composite mineralfiber web by means of said sixth means.
 65. The plant according to claim43, further comprising the following means in advance of said fifthmeans:k) twenty-third means for producing a seventh non-woven mineralfiber web defining a fourth longitudinal direction parallel with saidseventh mineral fiber web, said seventh mineral fiber web containingmineral fibers and including a third curable bonding agent, said seventhmineral fiber web being a mineral fiber web of a higher compactness ascompared to said second mineral fiber web, and l) twenty-fourth meansfor adjoining said seventh mineral fiber web to said second mineralfiber web produced by said third means in facial contact therewith,prior to folding said second mineral fiber web by means of said fifthmeans, for producing an eighth composite mineral fiber web to be foldedby means of said fifth means for producing said third non-woven mineralfiber web, and said seventh means also being adapted to cure said thirdcurable bonding agent.
 66. The plant according to claim 65, said seventhmineral fiber web being produced by separating a separate layer of saidfirst mineral fiber web therefrom and by compacting said separate layerfor producing said seventh mineral fiber web.
 67. The plant according toclaim 65, said seventh mineral fiber web being produced by separating aseparate layer of said second mineral fiber web therefrom and bycompacting said separate layer for producing said seventh mineral fiberweb.
 68. The plant according to claim 66, said compacting of saidseparate layer being performed by means of twenty-fifth means forfolding said separate layer so as to produce said seventh mineral fiberweb containing mineral fibers arranged transversely relative to saidfourth longitudinal direction of said seventh mineral fiber web.
 69. Theplant according to claim 43, further comprising twenty-sixth means forapplying a covering to a side surface or both side surfaces of saidthird mineral fiber web.
 70. The plant according to claim 56, furthercomprising twenty-seventh means for applying a covering to a sidesurface or both side surfaces of said fifth composite mineral fiber web.71. The plant according to claim 43, further comprising twenty-eighthmeans for cutting said cured third mineral fiber web into platesegments.
 72. The plant according to claim 56, further comprisingtwenty-ninth means for cutting said cured fifth composite mineral fiberweb into plate segments.
 73. The plant according to claim 43, saidseventh means being constituted by a curing oven.
 74. The plantaccording to claim 46, wherein the angle between the first mineral fiberweb relative to the first longitudinal direction is larger than about10° and smaller than about 60°.
 75. The plant according to claim 46,wherein the angle between the first mineral fiber web relative to thefirst longitudinal direction is larger than about 20° and smaller thanabout 50°.
 76. The plant according to claim 43, wherein the firstmineral fiber web comprises an area weight between 0.2 kg/m² and 0.6kg/m².
 77. The plant according to claim 49, wherein the second mineralfiber web comprises an area weight between 0.5 kg/m² and 2.0 kg/m². 78.A mineral fiber plate defining a first direction and comprising:firstand second lamellae arranged transversely relative to said firstdirection, said first and second lamellae containing mineral fibersarranged transversely relative to said first direction and transverselyrelative to one another, a surface layer applied to one side of saidfirst and second lamellae or opposite surface layers of identicalstructure, sandwiching said first and second lamellae in said integralstructure, and said fibers of said first and second lamellae beingbonded together in an integral structure solely through hardened bondingagents hardened in a single hardening process and initially present inuncured, non-woven mineral fiber webs from which said first and secondlamellae are produced.
 79. The mineral fiber plate according to claim78, said first and second lamellae being bonded together throughhardened bonding agents in a single hardening process and initiallypresent in uncured, non-woven mineral fiber webs from which said firstand second lamellae are produced.
 80. The mineral fiber plate accordingto claim 78, said first and second lamellae being interconnected throughmineral fiber layers of a higher mineral fiber compactness as comparedto said lamellae.
 81. A mineral fiber plate according to claim 78,wherein:said mineral fiber plate is contained in a sealed package, andsaid mineral fiber plate is kept in a compacted state within said sealedpackage in which state the overall volume of said mineral fiber plate isreduced 30-100% of the overall volume of said non-compacted mineralfiber plate through compacting said mineral fiber plate.
 82. The mineralfiber plate according to claim 81, said package including a plurality ofmineral fiber plates.
 83. The mineral fiber plate according to claim 81,wherein the overall volume of the mineral fiber plate within the sealedpackage is reduced 50-90% of the overall volume of the non-compactedmineral fiber plate.
 84. The mineral fiber plate according to claim 81,wherein the overall volume of the mineral fiber plate within the sealedpackage is reduced 60-80% of the overall volume of the non-compactedmineral fiber plate.
 85. A tubular insulating element comprising a bodycontaining mineral fibers bonded together in an integral structurethrough hardened bonding agents and being produced from a mineral fiberplate produced according to claim 78 and defining a first longitudinaldirection parallel with said non-woven mineral fiber web, a firsttransverse direction parallel with said non-woven mineral fiber web, anda second transversal direction perpendicular to said first longitudinaland transversal directions by cutting said tubular insulating elementfrom said non-woven mineral fiber web defining a second longitudinaldirection, said second longitudinal direction being parallel with saidfirst longitudinal direction, said first transversal direction, or saidsecond transversal direction or defining a specific angular relationshipwith said first longitudinal direction, said first transversal directionor said second transversal direction.
 86. The tubular insulating elementaccording to claim 85, said mineral fibers being bonded together in saidintegral structure solely through said hardened bonding agents hardenedin a single hardening process and initially present in uncured non-wovenmineral fiber webs from which said mineral fiber plate is produced. 87.The tubular insulating element according to claim 85, said mineral fiberplate constituting a mineral fiber plate assembly composed of aplurality of individual mineral fiber plate segments.
 88. The tubularinsulating element according to claim 85, said mineral fiber plate orsaid mineral fiber plate segments being produced from an uncurednon-woven mineral fiber web and being exposed to:compression along saidfirst longitudinal direction; compression along said first transversaldirection; compression along said second transversal direction; or acombination thereof; said compression occurring prior to, after, orprior to and after curing said uncured non-woven mineral fiber web. 89.The tubular insulating element according to any of the claim 85, furthercomprising an outer surface coating applied to said tubular insulatingelement, said outer surface coating being constituted by a plasticsfoil, a woven or non-woven plastics fiber foil, an aluminum foil, analuminum foil reinforced plastics foil, a fiber reinforced plasticsfoil, a crape paper covering, a glass fiber reinforced foil or acombination thereof.
 90. A method of producing a tubular insulatingelement, comprising the following steps:a) providing a non-woven mineralfiber web produced according to the method of claim 1 and defining afirst longitudinal direction parallel with said non-woven mineral fiberweb, a first transversal direction parallel with said non-woven mineralfiber web, and a second transversal direction perpendicular to saidfirst longitudinal and transversal directions, and b) cutting saidtubular insulating element from said non-woven mineral fiber webdefining a second longitudinal direction, said second longitudinaldirection being parallel with said first longitudinal direction, saidfirst transversal direction, or said second transversal direction ordefining a specific angular relationship with said first longitudinaldirection, said first transversal direction or said second transversaldirection.
 91. The method according to claim 90, said non-woven mineralfiber web constituting a non-woven mineral fiber web assembly composedof a plurality of individual non-woven mineral fiber web segments. 92.The method according to claim 90, said nonwoven mineral fiber web beingproduced from an uncured non-woven mineral fiber web and being exposedto:compression along said first longitudinal direction; compressionalong said first transversal direction; compression along said secondtransversal direction; or a combination thereof; said compressionoccurring prior to, after, or prior to and after curing said uncurednon-woven mineral fiber web.
 93. The method according to claim 76,further comprising the step:c) applying an outer surface coating to thetubular insulating element, the outer surface coating being constitutedby a plastics foil, a woven or non-woven plastics fiber foil, analuminum foil, an aluminum foil reinforced plastics foil, a fiberreinforced plastics foil, a crepe paper covering, a glassfiberreinforced foil or a combination thereof.
 94. A method of producing acured non-woven mineral fiber web comprising the following steps:a)producing a first non-woven mineral fiber web defining a firstlongitudinal direction parallel with said first mineral fiber web and afirst transversal direction parallel with said first mineral fiber web,said first mineral fiber web containing mineral fibers arranged in saidfirst longitudinal direction thereof and including a first curablebonding agent, b) moving said first mineral fiber web in said firstlongitudinal direction, c) arranging segments of said first mineralfiber web in partly mutually overlapping relationship and transverselyrelative to said first longitudinal direction and said first transversaldirection so as to produce a second non-woven mineral fiber web, saidsecond mineral fiber web defining a second longitudinal direction and asecond transversal direction and containing mineral fibers arrangedtransversely relative to said second longitudinal direction and saidsecond transversal direction and generally transversely relative to oneanother, said segments of said first mineral fiber web defining an anglelarger than about 10° and smaller than about 60° relative to said secondtransversal direction, d) moving said second mineral fiber web in saidsecond longitudinal direction, e) folding said second mineral fiber webtransversely relative to said second longitudinal direction and parallelwith said second transversal direction so as to produce a thirdnon-woven mineral fiber web, said third mineral fiber web containingmineral fibers arranged transversely relative to one another andtransversely relative to said second longitudinal direction and saidsecond transversal direction, f) moving said third non-woven mineralfiber web in said second longitudinal direction, and g) curing saidfirst curable bonding agent so as to cause said mineral fibers of saidthird mineral fiber web to bond to one another, thereby forming saidcured non-woven mineral fiber web.
 95. The method according to claim 94,wherein said segments of said first mineral fiber web define an anglelarger than about 20° and smaller than about 50° relative to said secondtransversal direction.
 96. A plant for producing a cured non-wovenmineral fiber web comprising:a) first means for producing a firstnon-woven mineral fiber web defining a first longitudinal directionparallel with said first mineral fiber web and a first transversaldirection parallel with said first mineral fiber web, said first mineralfiber web containing mineral fibers predominantly arranged generally insaid first longitudinal direction thereof and including a first curablebonding agent, b) second means for moving said first mineral fiber webin said first longitudinal direction, c) third means for arrangingsegments of said first mineral fiber web in partly mutually overlappingrelationship transversely relative to said first longitudinal directionand said first transversal direction so as to produce a second non-wovenmineral fiber web, said second mineral fiber web defining a secondlongitudinal direction and a second transversal direction and containingmineral fibers predominantly arranged generally transversely relative tosaid second longitudinal direction and said second transversal directionand generally transversely relative to one another, said segments ofsaid first mineral fiber web defining an angle larger than about 10° andsmaller than about 60° relative to said second transversal direction, d)fourth means for moving said second mineral fiber web in said secondlongitudinal direction, e) fifth means for folding said second mineralfiber web transversely relative to said second longitudinal directionand parallel with said second transversal direction so as to produce athird non-woven mineral fiber web, said third mineral fiber webcontaining mineral fibers predominantly arranged generally transverselyrelative to one another and generally transversely relative to saidsecond longitudinal direction and said second transversal direction, f)sixth means for moving said third non-woven mineral fiber web in saidsecond longitudinal direction, and g) seventh means for curing saidfirst curable bonding agent so as to cause said mineral fibers of saidthird mineral fiber web to bond to one another, thereby forming saidcured non-woven mineral fiber web.
 97. The plant according to claim 96,wherein the angle between the first mineral fiber web relative to thesecond longitudinal direction is larger than about 20° and smaller thanabout 50°.